Fall Snake Encounters

Fall Snake Encounters

As many of you know, I do programs with snakes and receive a lot of calls about them.  But in recent weeks I have seen an increase in the number of calls and the number of encounters inside of homes.  Though most of the home invasions have been in the garage, one found a gray rat snake in the cushions of her couch.  In addition to the home invasion calls I have also seen an increase with venomous snake encounters and thought I would write about the possible reasons for this increase. 

For many, snakes on the property is an unnerving situation. Photo: Molly O’Connor

Of the 48 species of snakes found in Florida, 40 are found in the western panhandle – where I live.  I decided to try a snake watch where they public would report what snakes they were seeing and what time of year.  As of September 15, there have been 54 reports.  32 of those (59%) were reported in April and May.  There are two explanations for this.  One, it is the beginning of spring and the warm temperatures have them moving from their wintering habitats.  Two, it is spring, and this is breeding season.  When breeding hormones are flowing snakes are bolder during their movements and may expose themselves more often in the search for mates.  It is also true that they have been in brumation during the winter when they feed very little and are need of food.  This could make them move more than normal as well. 

 I divided the species into subgroups mimicking publications by Dr. Whit Gibbons.  Based on this, in the western panhandle there are 7 species of small snakes, 8 mid-sized, 7 large snakes, 13 water snakes, 4 venomous snakes, and 1 non-native species.  The encounters by these subgroups so far include 1 of the 7 small snakes (14%), 3 of the 8 mid-sized snakes (38%), 5 of the 7 large snakes (71%), 5 of the 13 water snakes (38%), 3 of the 4 venomous snakes (75%), and the non-native Brahminy Blind Snake has not been reported yet. 

The eastern king snake is one of the larger snakes in the western panhandle. Photo: Rick O’Connor

The high percentage of large snake encounters makes sense because they are – well… large and easier to see.  The explanation for the high percentage of venomous snake encounters is numbers.  There are only four species to be found in the western panhandle.  It does not take many encounters to get a high percentage. 

Water snakes will be encountered only if folks are visiting local waterways and are relatively still while there.  My guess is that most encounters were from basking snakes or ones swimming across a body of water in which the observer happened to be there.  Most snakes will freeze and hide when they since we are near, and most are well camouflaged.  There are plenty of people who visit local waterways where these snakes exist.  The lower percentage of encounters with this subgroup does not mean they are not there; they were just not seen.  Many reports come from fishermen who are relatively still in their boats while fishing.  If you move, they stop.  If you stop, they move – and more will be seen. 

The banded water snake is one of the more commonly encountered water snakes. Photo: Rick O’Connor

If you look at the encounters by species, we have found 17 of the 40 western panhandle species have been encountered so far (43%).  There has been a total of 54 encounters.  Most, 13 (24%) have been with the southern black racer.  This is a common large snake that does very well in human habitats like our neighborhoods and parks.  It is active during the day and is fast enough to avoid trouble so may be more willing to expose themselves than other species.  They also have a preference for more open spaces where they can be seen. 

The southern black racer differs from other black snakes in its brilliant white chin and thin sleek body. Photo: Jacqui Berger.

The second most frequently encountered snake so far this year has been both the eastern ribbon snake and the cottonmouth – 9 reports of both.  The two account for 33% of all reports.  Eastern ribbon snakes are fans of water and are often found along the edge of water bodies.  With the increase in rainfall, many areas are wetter and encounters with this mid-sized snake have increased.  They are most active during the day, especially on warm days, and this may also play a role in why they have been seen more often than other species. 

The cottonmouth is an interesting story.  Of the four species of venomous snakes, three of these have been encountered, and their encounters make up 15 of the 54 so far this year (28%).  Of the 15 encounters, 9 were cottonmouths (60% of the venomous snake encounters, and 17% of all snake encounters reported).  It is a commonly encountered snake.  Seeing the cottonmouth as one of the top three encountered snakes in our area makes some people nervous.  Like some of the other commonly encountered snakes, they like water – and there is plenty of it in the western panhandle.  They prefer quiet water locations such as ponds, swamps, and lakes.  They frequent water holes on golf courses and retention ponds in neighborhoods.  It is also obvious that new developments are going up closer to wetlands than they did in the past – which would increase your chances of encounters.  I recently completed a three-year survey of a gated community on Perdido Key where encounter rates were high.  The interesting thing here is that barrier islands have little freshwater and are not classic cottonmouth habitat.  But for decades there have seen an increase in encounters, which prompted many studies on how they are surviving.  There are certainly natural freshwater systems on both Perdido Key and Santa Rosa Islands, but we have also created such habitats as well.  It is possible that the cottonmouth is better suited to exploit these island habitats than other species of water snakes and thus are encountered more often.  I plan to do more surveys for this, and other water snakes, on our islands beginning in 2023 and will let everyone know what we discover. 

The cottonmouth is one of the more commonly encountered snakes in the western panhandle. Photo: Bob Jackson

So, what has triggered the recent increase in home invasion and other snake encounters?

A week or two ago we experienced massive amounts of rainfall when a frontal system passed over.  You might remember the flooding that occurred in Dallas TX and Jackson MS.  That same system passed over us and generated a lot of rainfall.  Like many animals, when water levels are up, they seek higher ground.  During such events snakes are often reported in garages, porches, even in walls of homes.  People were telling me they were finding them in the bathrooms, hallways, and even in the cushions of their couches.  All of those reported were non-venomous, but cottonmouths are often encountered during these flooding events as well.   

Other encounters can be explained as they were in the spring – the weather is changing.  You may have noticed the recent decrease in humidity as a front passed over.  It is not cold yet, but the lower humidity is signaling the oncoming fall season – and the snakes’ sense this as well.  15 of the 40 species (38%) in the western panhandle have a fall breeding season in addition to the spring one.  All of the pit vipers breed in the fall and the rattlesnakes prefer fall breeding to spring.  With the oncoming of the fall, males will be out seeking females.  And as we mentioned earlier, hormones will force you to move more in the open than they may typically do. 

This eastern diamondback rattlesnake was seen crossing a dirt road near DeFuniak Springs shortly after the humidity dropped. Photo: Lauren McNally

We will continue our snake watch for the rest of the year and will give an update early in 2023.  If you do see a snake, please let us know which species and which month you encountered it.  If you have questions about snake encounters and snake safety, do not hesitate to contact your county extension office. 

Discovering Dissolved Oxygen

Discovering Dissolved Oxygen

We all know how important oxygen is to all life.  It is an element with the atomic number of 8, meaning it has eight protons and eight electrons.  It has an atomic mass of 16 indicating that it also has eight neutrons.  Oxygen is a gas at room temperature indicating that 70°F is VERY hot for this element.  It is a diatomic molecule, meaning that it likes to combine with other elements and will combine with itself if need be.  Oxygen is not actually O, it is O2 in nature.  There is a triatomic form of this element, O3, which is called ozone – but that is another story.

Again, we know oxygen is much needed by living organisms.  Well… by most living organisms – there are some microbes that can survive with little or no oxygen, but for the majority of the creatures we are familiar with, it is a must. 

I have asked students why oxygen was so important to life.  I usually get the answer “that we will die without it”.  I respond by asking again – “but WHY do we need it?  What does it DO?”  And the response usually does not change – “we must have it or we will die”.  There is no doubt that it is important.  Being in an atmosphere with little or no oxygen sends our bodies into a “stress mode” gasping – but what DOES the element actually do for us? 

Life is abundant on this planet due to the presence of oxygen. Photo: Rick O’Connor

Oxygen is needed to complete the reaction we call respiration.  For most, the term respiration means “breathing” and this would be correct – but it is more than that.  It is an oxygen demanding reaction we all need to remain alive.  In this reaction the sugar molecule glucose (C6H12O6) is oxidized to produce Adenosine triphosphate (ATP – C10H13N5O13P3).  ATP is the “energy” molecule needed for cells to function – our gasoline.  It fuels all metabolic reactions needed to sustain life.  ATP cannot be consumed in food, it must be made in the cell and, as the reaction below shows, it requires sugar (which we get from food) and oxygen (which we inhale from the atmosphere) to work.

C6H12O6 + O2 –> CO2 + H2O + ATP

This reaction will produce 36 of the much-needed molecules of ATP with each cycle.  It is known that in anaerobic respiration (the break down of glucose without oxygen) it will also produce ATP but not as much – only 2 molecules of it instead of 36.  So, for most creatures’ aerobic respiration (with oxygen) is preferred and needed.  

The primary source of oxygen on our planet is plants.  This suggest that before plants existed there may have been little, or no, oxygen on in our atmosphere and scientists believe this was the case.  When you look at the fossil records it suggests that prior to plants existence there was life (anaerobic life) but after plants the diversity and abundance of life exploded.  Aerobic respiration seems to be the way to go. 

As most know, plants produce oxygen in the process known as photosynthesis.  This chemical reaction is used by the plants to produce the other needed respiration molecule glucose.  Plants produce their own glucose and so are called producers, while other creatures, including animals, are consumers – consuming glucose in their food.  The reaction for photosynthesis is –

CO2 + H2O –> C6H12O6 + O2

The excess oxygen produced in this reaction is released into the atmosphere by the plants.  It makes up 20% of our atmosphere and this allows life as we know it to exist.  Note… almost 50% of the oxygen in our atmosphere comes from single celled algae called phytoplankton that grow and exist at the surface of our oceans.    

Single celled algae are the “grasses of the sea” and provide the base of most marine food chains. Photo: University of New Hampshire

But what about aquatic creatures who do not breath the atmosphere you and I do?  How do they obtain this much needed oxygen drifting in our atmosphere? 

The answer is in dissolved oxygen.  Oxygen, being a gas, is released into the atmosphere.  Even the oxygen produced by submerged aquatic plants, like seagrasses and algae, release their oxygen as a bubble of gas which floats to the surface, pops, and is released to the atmosphere.  To get that back to the creatures in the water who need it as much as we do, you have to “dissolve” it into the water. 

To do this you must break the hydrogen bonds that connect water molecules to each other.  Water is a polar molecule, and each molecule connects to each other like magnets using hydrogen bonds.  These hydrogen bonds are weak and easy to break, but you must MOVE the water in order to do this. 

The water molecule. Image: Florida Atlantic University

Water movement, such as waves, currents, and tides, will do it.  The more movement you have the more oxygen will dissolve into it.  Waterways such as the rapids of mountain rivers and waterfalls will have high concentrations of dissolved oxygen – usually over 10 µg/L.  For some creatures this could be too high – like an oxygen rush to the head – but for others, like brook trout, it is perfect.  They do not do well in water with dissolved oxygen (DO) concentrations less than 10. 

For most waterways the DO concentrations run between 4 and 10 µg/L.  Most systems run between 5-7.  Waterways with a DO concentration less that 4 µg/L are termed hypoxic – oxygen deprived – and many creatures cannot live at these levels.  They are literally gasping for air.  I have seen fish at the surface of our local waterways when the DOs are low gasping for much needed oxygen through the atmosphere.  It is also the primary reason the great crab jubilees of Mobile Bay occurs.  Low levels of DO in the bay will trigger many creatures to leave seeking higher DO in the open Gulf.  But for some benthic creatures – like stingray, flounder, and blue crabs – they will literally run onto the beach gasping for oxygen.  The fish known as menhaden are particularly sensitive to low DOs and are one of the first to die when concentrations begin to dip below 4.  When you see the surface of a waterway littered with dead menhaden it typically means there is a DO problem. 

Slick calm water diffuses/dissolves less oxygen. Photo: Molly O’Connor

That said, some creatures, like catfish, can tolerate this and do not become stressed until the concentrations get below 2 µg/L.  If they ever reach 0 µg/L (and I have seen this twice – once in Mobile Bay and once in Bayou Texar) the waterway is termed anoxic – NO oxygen.  This is obviously not good.  Some are familiar with the “Louisiana Dead Zone”.  An area of the open Gulf of Mexico south of the Mississippi River where DO levels decline in the summer to levels where most benthic species, particularly shrimp, are hard to find.  It seems “dead” – void of marine life.  This is also a DO issue. 

How – or why – do dissolved oxygen levels get that low?

There are three basic reasons to this answer. 

  1. The surface is still, and little atmosphere oxygen is being “dissolved”.  We have all seen calm days when the water is as slick as glass.  On days like these, less oxygen is being dissolved into the system and the DO concentrations begin to drop.  But how low will they go? 
  2. The water is warm.  Higher water temperatures hold less oxygen.  As the water warms the oxygen “evaporates” and the DO concentrations begin to decline.  If it is a warm calm day (like those during a high-pressure system in summer) you have both working against you and the DO may drop too low.  Most fish kills due to DO concentrations occur during the hot calm summer days. 
  3. What is called biological oxygen demand.  All creatures within the system demand oxygen and remove it from the water column.  However, in most cases, atmospheric dissolved oxygen will replace for a net loss of zero (or close to it).  But when creatures die and sink to the bottom the microbes that decompose their bodies also demand oxygen.  If there is a lot of dead organic material on the bottom of the waterway that needs to be broken down, the oxygen demanding microbes can significantly decrease the DO concentrations.  This dead organic material is not restricted to fish and crabs that die but would include plant material like leaves and grass clippings from our yards, organic waste like feces, food waste, the carcasses of cleaned fish, any organic material that can be broken down can trigger this process. 

Now picture the perfect storm.  A hot summer day with no wind and high humidity over a body of water that has heavy organic loads of leaves, dead fish carcasses, and waste.  BAM – hypoxia… – low DO… fish kill… which would trigger more oxygen demanding decomposition and – more dead fish – a vicious cycle.   

You have probably gathered that low dissolved oxygen concentrations can occur naturally – and this is true – but they can also be enhanced by our activity.  Allowing organic material from our yards (grass clippings, leaves, and pet waste) to enter a body of water will certainly enhance the chance of a hypoxic condition and a possible fish kill – which would in turn fuel lower DO and poor water quality state for that body of water.  The release of human waste (food and garbage, sewage, etc.) will also trigger this.  And throwing fish carcasses after cleaning at the boat dock will too. 

But there is another process that more people are becoming familiar with that has been a problem for some time.  The process of eutrophication.  Eutrophic indicates the waterway is nutrient rich.  These nutrients are needed by the plants in order to grow – and they do.  Particularly the single celled algae known as phytoplankton.  These phytoplankton begin to grow in huge numbers.  So, abundant that they can color the water – make it darker.  As mentioned above, they produce a lot of oxygen, but at night they consume it, and with SO much phytoplankton in the water they can consume a large amount of DO.  The DOs begin to drop as the evening wears on and before sunrise may reach concentrations low enough to trigger a fish kill.  These phytoplankton will eventually die and with the large mass of organic matter sinking to the bottom, the oxygen demand to decompose them can trigger larger fish kills.  These fish kills in turn demand more oxygen to decompose and the process of eutrophication can create a waterway with very poor water quality and a habitat unsuitable for many aquatic creatures.  It is not good.  This is the process that causes the Louisiana Dead Zone each summer.  The nutrients are coming from the Mississippi River. 

One of 39 stormwater drains into Bayou Texar that can introduce a variety of organic compounds that can fuel eutrophication. Photo: Rick O’Connor

So, is there anything we can do to help reduce this from happening?

Well, remember some hypoxic conditions are natural and they will happen.  But there are things we can do to not enhance them or trigger them in waterways that would otherwise not have them. 

  1. When raking your yard, place all leaves in paper bags for pick up.  This keeps the leaves from washing into the street during rain events (and we are getting plenty of those) and eventually into a local waterway.  The problem with using plastic bags is that the local utility who collects them can no longer compose this into mulch.  You might consider using your leaves and grass clippings for landscaping yourself. 
  2. Watch fertilization of your yard.  Many over fertilize their yards and the unused fertilizer is washed into the street and eventually into the local waterway.  These fertilizers will do to phytoplankton what they were designed to do with your lawn – make them grow.  Of course, not fertilizing your yard would be best, but if you must place only the amount, and type, your lawn needs.  Your extension office can help you determine what that would be. 
  3. Pick up pet waste when you take your pets out to go to the bathroom. 
  4. If you have a septic tank – maintain it.  You can also look into converting to a sewer system. 
  5. If you are on sewer – watch what you pour down the drain.  Many products – such as fats, oils, and grease – can create clogs that cause sanitary sewage overflows when we have heavy rains (and we will have heavy rains).  Our local utility in the Pensacola area offers the FOG program (Fats, Oils, and Grease).  In this program you can pick up a clean 1-gallon plastic container to pour your fats, oils, and grease into.  Once full, you bring it back and switch for a clean empty.  To find where these containers bins are located near you visit the ECUA website – https://ecua.fl.gov/live-green/fats-oils-grease.
1-gallon container provided free to dispose of your oil and grease. Photo: Rick O’Connor

Dissolved oxygen concentrations naturally go up and down, and sometimes low enough to trigger a natural fish kill but following some of the suggestions above can help reduce how frequently these happen and can help to make our estuary healthier. 

Mountains of Jellyfish

Mountains of Jellyfish

In recent weeks there have been reports of large masses of jellyfish along the Gulf Coast.  I have actually heard people state “I would rather be in the water with 100 sharks than 100 jellyfish”.  Maybe that is true from some.  Honestly, it seems dealing with sharks could be easier.  Jellyfish are just there in a swarm.  The more you try to move them away, the more they come towards you – it is like trying to avoid the smoke from a campfire. 

But jellyfish exist and people sometimes have to deal with them.  The thing they hate about them, of course, are their painful stings.  As Jimmy Buffett puts it – “They are simple protoplasm – clear as cellophane – they ride the winds of fortune – life without a brain”.  This is prreeettttyyyyy close. 

Jellyfish are common on both sides of the island. This one has washed ashore on Santa Rosa Sound.

The “cellophane” jelly material is called mesoglea and it is a protein-based material that is 90% water.  Lay a jellyfish on a deck and see what is left at the end of the day – not much.  The bell undulates rhythmically controlled not by a brain but by a series of nerves – what some scientists call a “nerve net”.  At the base of the bell is a single opening – the mouth.  There are no teeth and whatever they swallow enters a simple gut where digestive enzymes do their work.  But it is the only opening – so, waste material must exit through the same opening.  Yes… they go to the bathroom through their mouth.  Nice eh…

Then there are the tentacles – those lovely tentacles.  These are armed with small cells called nematocysts that harbor a small dart tipped with a drop of venom.  Each nematocyst as a small trigger which, when bumped, will fire the dart injecting the venom.  When you bump a tentacle, you are literally bumping hundreds of these nematocysts and receive hundreds of drops of venom.  Some species hurt, some do not.  Those that hurt are no fun. 

So, why SO many at one time in one place? 

Most jellyfish feed on small food.  Those food sources tend to multiple when the water is warm (and it is warm right now) and there are lots of nutrients in the water.  When we have heavy rain (and we have had heavy rains this year) the runoff introduces large amounts of nutrients to the system.  Warm nutrient rich water mean increase in jellyfish food, which in turn means increase in jellyfish.  With winds and tides working together (and we saw this with the recent front that passed through), the jellyfish are shoved into smaller locations.  In recent weeks that has been close to shore and the thick masses of jellyfish we have witnessed. 

They do fly the purple flags when jellyfish are spotted.  It us unusual for them to be a problem on both the Sound and Gulf sides.  So, usually if they are bad on the Gulf side, you can move your beach day to the Sound and be fine.  And remember – this too shall end.  It won’t last forever. 

The Pensacola Bay Horseshoe Crab Hunt 2022

The Pensacola Bay Horseshoe Crab Hunt 2022

This is an amazing animal – the horseshoe crab (Limulus polyphemus).  A relic of an age before the dinosaurs, they have been plowing the sediments of our marine and estuarine waters for over 400 million years. 

They are thick armored tanks, shaped like horseshoes with a long spikey tail giving them appearance of a stingray.  They are usually a deep green color, though some have a brownish hue, and have two lighter colored eyes on each side of the head, though there is a third you cannot see.  They crawl across the bottom of the Gulf and bays seeking smaller invertebrates to eat. Their armor protects them from most predators, but they do have a few, like the loggerhead sea turtle.  Though harmless to people, they don’t appear that way with numerous spines running along their abdomen and the long spine extending from the rear on a ball and socket joint that allows them to swing it, albeit slowly, in circles.  They are pretty cool actually. 

This female is carrying a male on a beach in Big Lagoon within the National Seashore. Photo: Bob Pitts

They are actually not crabs.  They are in the Phylum Arthropoda, like crabs, but not in the Subphylum Crustacea, as crabs are.  Rather they are in the Subphylum Chelicerata and more closely related to the arachnids like spiders and scorpions.  There are four species of these creatures remaining on the planet, three of those live in Asia, one along the Atlantic and Gulf coast of the United States. 

Horseshoe crabs vary in size throughout their range but are typically between one to two feet in length and up to one foot across the head.  This would be the size of a large female; males are much smaller. 

They are benthic creatures exploring the bottom of both the bays and the open oceans searching for food. 

Life for a horseshoe crab begins on the shore.  Mom buries her eggs in the sand at the tideline during the spring high tide of either the spring or fall season.  They young emerge between two and four weeks and begin life as plankton (though they resemble the adults at this stage).  They eventually settle out as juveniles in the seagrasses near where they were born and begin their life as benthic creatures.  The large adults eventually work their way out into the open ocean to feed before returning to start the cycle over. 

A large horseshoe crab found in Little Sabine. Photo: Amanda Mattair

When the females return, smaller males pursue her to shore in hopes of being the one to fertilize her eggs.  Many times, a male will use a modified claw that resembles a hook to grab on to the back of the female and ride in with her.  But several other males, called satellites, will continue across the bottom in pursuit.  Once on the beach she will begin to deposit her eggs in the sand at high tide and the males rush in to fertilize.  Studies show that more often than not it is one of the satellites who is successful.  And so, it goes over their 20 year life span, and this has been going on for hundreds of millions of years. 

Their range extends from the Gulf of Maine to the Gulf of Mexico.  Populations within this range have declined in recent years and there have been efforts throughout to manage this problem.  Here in Florida the Florida Fish and Wildlife Conservation Commission (FWC) has developed a citizen science project they call The Florida Horseshoe Crab Watch where volunteers visit nesting beaches to collect information from the animals and tag them.  Here in Pensacola Bay, though we have seen horseshoe crabs, we have not identified any nesting beaches and that is the focus of our Pensacola Bay Horseshoe Crab Hunt… to find those nesting beaches. 

In 2017 we began marking horseshoe crab sightings in the Pensacola Bay area on a map.  The purpose of this was to determine if there were “hotspots” (locations that had repeated sightings) that we could use to search for nesting locations.  Beginning in 2020 we trained citizen science volunteers to survey one of nine such hotspot locations.  Each of these were laid out with beach walking transects that ranged from 0.30 to 0.95 miles in length (mean = 0.69 miles). 

In 2022 we trained 14 volunteers in March to survey these transects.  They were instructed to visit one of the nine locations ± 30 minutes of spring high tide during the spring months (April-June).  All of the spring tides were provided to them, but they had to use an outside resource to determine what time high tide as their location.  Each volunteer was provided an FWC data sheet to complete after each survey and submit these to the local Sea Grant Extension Agent. 

This horseshoe crab pair was found on shore near Wakulla Florida. Photo: Charles Pulley

12 of the 14 volunteers (86%) did conduct at least one survey.  These surveys covered six of the nine transect locations (67%) and others surveyed nine new locations. 

A total of 77 surveys were conducted during the spring of 2022 for a total of 23.7 miles and logging 77 hours.  No horseshoe crabs were sighted, and no nesting beaches were found. 

That said, the general public continued to call in sighting reports outside of the official surveys.  Six residents sent the Sea Grant Extension Agent records of sightings at six locations around the bay area.  Three of these were locations were transect locations we are currently surveying, further confirming these are good places to search.  Those three were Big Sabine, Little Sabine, and Sharp Point on Pensacola Beach.  The other three locations included Portofino and the point at Ft. Pickens on Pensacola Beach as well as Navarre Beach

Locations that were surveyed and no sightings were reported included Park West and Morgan Park on Pensacola Beach, Naval Live Oaks in Gulf Breeze, Sanders Beach and Bayou Grande in Pensacola, and Galvez Landing, Perdido Key State Park, Big Lagoon State Park and Tarkiln Bayou out near Perdido Key. 

We will continue to search these sites each year in hopes of finding nesting horseshoe crabs.  We encourage everyone to continue to report sightings to the Sea Grant Extension Agent in Escambia County (850-475-5230; roc1@ufl.edu ) and consider becoming a volunteer in the spring. 

Horseshoe crab molts found on the beach near Big Sabine. Photo: Holly Forrester.
Buggin’ Out! When the Outdoors Comes Indoors

Buggin’ Out! When the Outdoors Comes Indoors

AUTHOR: ETHAN CARTER – Regional Agriculture Specialist; Northwest District

While many people enjoying hiking and exploring the outdoors, coming home to find unexpected bugs in the house is much less enjoyable.

There are several key factors that generally lead insects to a home: stored products, lights (windows, doorways), people and pets.

Stored Products

One of the most common reasons that many types of insects get into a home and complete their life cycles is directly related to food sources and human action. Once the population is large enough, individuals are found throughout the house, but their source is usually uncertain. Beetles and weevils are generally attracted to grains and the pantry is generally the first-place people start to look, through the oatmeal, rice, and other foods. However, the pantry tends to be a dead end in lots of instances and then people will just call pest control to come treat. In this scenario, drugstore beetles are a common nuisance.

Figure 1. Adult drugstore beetle. Photo by B.J. Cabrera, University of Florida.

What they don’t think about is other suitable food sources for household pests that tend to be stored in closets, spare rooms, attics, and garages. Dried flower arrangements, decorative Indian corn, bean or macaroni art, bird seed, fish food, flower bulbs, tobacco products, and old books or papers. A common example of a household pest that favors paper goods is the silverfish

Figure 2. Adult Silverfish. Photo by Larry Reeves, University of Florida.

Another very common household pest is the drain fly. Commonly confused as fruit flies, the drain fly is commonly found around poorly maintained drains (kitchen, shower, etc.). They feed on organic matter such as hair, soap, and other decaying materials.

If rodents are or have been present in the home, their food stores behind shelving, refrigerators, or in the walls can also act as ground zero for ballooning insect populations. Animal fiber products (hair, rugs, etc.) and cotton can also be a food source for different species of beetles and moths.

Lights

Evening hours and lights tend to bring a number of insects to the home.

Figure 3. Moth attracted to a light. Photo by Fir0002 at en.wikipedia.

These range from small flies, roaches, beetles, and moths. Some may crawl up the side of the house or door, while others will fly around the lights. Open windows or people entering and exiting the home after exterior lights have been on for a while increase the risk of insects getting inside. What’s more, frogs and lizards are attracted to areas where insects congregate, and they can also get inside through poorly sealed doors and windows.

People and Pets

A random assortment of creatures (insects, scorpions, spiders, mites, frogs, etc.) can enter the home with the help of unsuspecting people. The most common source materials include firewood, potted plants, and wooden materials (shelves, tables, fireplace mantels, etc.). Larger creatures can generally be connected to firewood or potted plants after the fact, while small beetles can be more difficult to place. Powder post beetles are common wood destructive pests that can occur in households and can generally be traced back to recently constructed or purchased materials brought inside the home. The early part of their life cycle is spent within the wood, but at the end of their life they exit creating a series of holes and leaving their trademark ‘powder’ or dust on the floor.

People and pets are common vectors for several parasitic bugs, including bed bugs, lice, ticks, and fleas. Bed bugs and lice can come from traveling and staying at already infected areas, they travel in luggage or on clothing. Lice are also easily vectored by sharing clothing, especially among children with hats and brushes. Pets can bring fleas and ticks into the house. Fleas may establish a population depending on the cleanliness of the residence, including carpeted areas, pet bedding, and even blankets. Ticks are relatively uncommon, they tend to stay on their food source once attached but can occasionally be dislodged while petting or brushing a pet and found later.

Figure 4. Adult male (left) and female (right) Lone Star Ticks. Photo by Lyle Buss, University of Florida.

When curious to learn more about insects found in the home, free diagnostic samples can be sent to the FDACS Division of Plant Industry or for a nominal $8 fee, the UF Insect ID Lab. For more information contact your local extension agent.