House Fly Control

Signs of a House Fly Infestation and Fly Control

House flies are attracted to food sources, water, and light. Swarms of flies are common around decomposing waste, where they can get both food and moisture. Look for fly larvae (maggots) in waste and rotting food. The small white worms eat hardily for several days before pupating into their adult form.

When house flies are nearby, you may hear the telltale buzzing noise of their wings beating together. Listen for the sound around garbage, dumpsters, drainpipes, and light fixtures.

A fly on a white background.

Treatment and Prevention

The best way to remove house fly infestation is to impede their ability to reproduce indoors. Do not allow organic material of any kind to accumulate around your building. Keep dumpsters clean and tightly sealed. Remove pest waste and don’t leave any type of food out.

House flies enter buildings through small cracks around screens, frames, or utility lines. Find and seal these gaps to keep the flies out. Replace damaged screens immediately. Invest in screens for your ventilation systems and exhaust points.

Facts About Flies and Identification

Behavior and Diet

House flies can only ingest liquid food. They feed on solid food by regurgitating saliva onto it until the food liquifies. This process demands that flies constantly seek out water for rehydration.

House flies feed on any material that’s moist, soft, and easily accessible. They’re particularly fond of decaying organic material like grass or fecal matter or fermenting material like mold or alcohol. They prefer warmer weather and are more active when temperatures rise.

How flies reproduce

House flies undergo a complete metamorphosis with egg, larval, pupal, and adult stages. Under ideal conditions, this life cycle could complete in as few as seven days.

A single female house fly can lay up to 500 eggs over three or four days. These eggs hatch within eight to 20 hours. Larvae eat nearby food until they grow large enough to pupate. Metamorphosis takes two to 27 days. Flies emerge from pupae ready to reproduce.

More Information

Penn State Dept of Entomology House flies fact sheet

University of Florida Dept of Entomology & Nematology House flies “Featured Creatures” sheet

World Health Organization Water Health Vector control report “Chapter 6 – House flies

Fly FAQ

How long do flies live?

House fly lifespans largely depend on temperature. It may take flies longer to mature in cold temperatures than it would during warm months. Adult flies live 15-30 days on average.

How long can a fly live live without food?

Without food, and particularly food with sugar, house flies will only last 2-3 days before they die. The females need this sustenance to lay their eggs.

How many eggs do flies lay?

Females are nearly instantly fertile once they emerge as adults. They procreate quickly, laying up to 500 eggs which hatch within 24 hours. If they have enough heat and food, house flies may produce twelve or more generations in a single year.

Do flies transmit diseases?

House flies are considered disease transmitters because they may touch feces or stagnant water before touching other food sources. Flies can transmit some 65 diseases including cholera, tuberculosis and typhoid.

What do flies eat?

Flies are opportunistic but prefer moldy and rotten foods, decomposing matter and animal waste. They can survive without food or water 2-3 days.

What attracts flies?

Flies are attracted to rotting food and decaying organic matter. This might include spoiled produce, open garbage containers, dead animal carcass, feces and pet waste, pet food, drain scum, and sweet liquids like juice or soda. Flies have an extraordinary sense of smell and can detect rotting food from up to four miles away. They’re also attracted to bright lights.

Why do I have flies in my house?

The most common reason is that they’re seeking sources of food and water. Flies need a steady source of water to be able to digest their food. At night they may be attracted to your lights and in the fall, they may be seeking to escape the cold.

How do flies get in the house?

Flies will use any entry they can find including open doors and windows, holes in screens, cracks in siding and ventilation outlets. Make sure you repair and home fissure and cover openings such as chimneys and vents. A pest control expert can help you locate these entry points.

Where are flies coming from?

Flies lay their eggs in rotting organic matter and animal waste. Once those eggs hatch, the larvae go through three stages of growth before they pupate into adult flies. If you have flies in your home, they are likely hatching nearby in your garbage or compost pile. Outside flies enter via open doors, torn screens and vents.

How to get rid of flies?

Keeping a clean, secure home is your best defense. Keep food covered, remove trash frequently and repair all cracks and gaps. A pest control professional can help identify the source of your infestation, treat against flies and perform more involved treatments like drain cleaning or trash chute cleaning.