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.

Rick O'Connor
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