The fastest way to stop flies is to remove what attracts them
Flies breed in wet manure and decomposing food, so the single most effective step is cleaning out wet bedding and spilled feed at least twice a week. A coop that stays dry and clean will have far fewer flies than one where moisture sits. If you have a serious fly problem right now, start by removing all wet bedding, scrubbing down surfaces with a stiff brush, and letting the coop dry completely in sunlight.
The second step is to store feed in sealed metal or plastic containers with tight lids. Flies lay eggs in exposed grain and pellets within hours. Even a small pile of spilled feed under the feeder can become a breeding ground in three to five days. Sweep up spilled feed when ready after each feeding, and do not leave feed sitting in the coop overnight.
Water is equally important. Chickens need fresh water, but standing water in troughs or puddles is where fly larvae develop. Empty and refill waterers daily, tip out any pooled water under roosts, and make sure the ground around the coop drains properly so water does not collect after rain.
Key Takeaways
- Remove wet bedding and manure at least twice a week, because fly larvae develop in moist conditions within three to five days.
- Store all feed in sealed containers and sweep up spilled grain when ready, since exposed feed attracts egg-laying flies within hours.
- Empty and refill waterers daily and drain standing water around the coop, because stagnant water is where fly larvae hatch.
- Lime powder spread on the floor absorbs moisture and kills some fly larvae, though it works best combined with regular cleaning rather than alone.
- Fly traps and predatory insects like parasitic wasps can reduce fly numbers but will not solve the problem if manure and feed remain wet.
Using lime powder and diatomaceous earth to slow fly breeding
Agricultural lime (also called hydrated lime or calcium hydroxide) absorbs moisture from wet bedding and manure, which makes the environment less suitable for fly larvae. Spread a thin layer—about a quarter inch—over the coop floor after you remove wet bedding. The lime dries out the surface and creates an alkaline environment that kills some developing larvae. Reapply after cleaning or when the floor becomes damp again.
Food-grade diatomaceous earth works differently: the powder damages the outer coating of fly larvae and adult flies, causing them to dry out. Dust it lightly over bedding and around feed areas. Both products are safe for chickens when used as directed, but avoid breathing the dust yourself—wear a mask when explore. Neither product replaces regular cleaning; they work best as a supporting step after you have removed wet material.
Fly traps and sticky strips for catching adults
Sticky traps and fly paper catch adult flies but do nothing to stop breeding. They are useful for monitoring how many flies you have and for reducing the population once you have cleaned up the coop, but they will not solve a fly problem on their own. Hang sticky traps near the coop entrance and in corners where flies tend to gather. Replace them when they are covered.
Some beekeepers and small-flock owners use parasitic wasps (tiny insects that lay eggs in fly pupae) to reduce fly numbers over time. These are sold by mail and released into the coop. They work slowly—it takes several weeks to see a reduction—and they work best when the coop is already cleaner. They are not a substitute for removing wet bedding and feed.
Managing manure piles outside the coop
If you keep a manure pile near the coop, it becomes a fly factory. Flies breed in the pile and fly back into the coop to lay more eggs. Cover the pile with a tarp or move it at least 20 feet away from the coop. If you compost manure, turn it regularly (at least once a week) so the heat kills fly larvae. A hot compost pile—above 130°F in the center—will kill fly pupae within days.
If you spread manure on pasture or garden, do it in early spring or late fall when fly activity is lowest. Spreading fresh manure in summer is one of the fastest ways to create a neighborhood fly problem, since flies will breed in the spread material and fly back to your coop and your neighbors' properties.
Ventilation and sunlight to keep bedding dry
Poor ventilation traps moisture inside the coop, which keeps bedding damp and creates ideal conditions for fly breeding. Make sure air can flow through the coop—install vents near the roof (where warm, moist air rises out) and near the floor (where fresh air comes in). Vents should have hardware cloth to keep predators out but allow airflow.
Sunlight also dries bedding and kills some fly larvae. If your coop is in shade, consider trimming back trees or moving the coop to a sunnier spot if possible. Even a few hours of direct sun each day makes a difference. If the coop must stay in shade, increase ventilation and clean more frequently.
Choosing bedding that dries quickly
Some bedding materials hold moisture longer than others. Pine shavings and straw absorb water and stay damp, which encourages fly breeding. Sand and pea gravel drain quickly and dry in sunlight, making them better choices if flies are a persistent problem. If you use shavings or straw, spread them thinner so they dry faster, and replace them more often—weekly rather than monthly.
Avoid using sawdust or fine wood chips, which compact and trap moisture. If you have a wet climate or poor drainage around the coop, switching to sand or gravel and cleaning twice weekly will reduce flies more than any other single change.
Keeping chickens healthy during fly season
Flies do not directly harm healthy chickens, but large numbers can stress birds and carry bacteria. Chickens will peck at flies and eat them, which is natural behavior. However, if flies are so thick that chickens cannot escape them or if you see signs of stress (birds staying huddled, not eating normally), the fly population is too high and you need to clean more aggressively.
A clean, dry coop is also healthier for chickens in general—it reduces disease risk and keeps birds more comfortable. The same practices that stop flies (removing wet bedding, storing feed properly, draining water) also prevent coccidiosis, respiratory illness, and other common coop problems.
Frequently Asked Questions
How long does it take to see fewer flies after I clean the coop?
You should see a noticeable drop within three to five days if you remove all wet bedding and keep the coop dry. Fly larvae take about five to seven days to develop from egg to adult, so breaking that cycle by removing wet material stops new flies from emerging. If flies return quickly, it means moisture is building up again—check for leaking waterers or poor drainage.
Will chickens get sick from eating flies?
Chickens naturally eat flies and insects, and this is not harmful. However, if flies are carrying disease from contaminated manure, they can spread bacteria like E. coli or Salmonella. The risk is low in a clean coop but higher in a dirty one, which is another reason to keep bedding dry and remove manure regularly.
Can I use pesticide sprays in the coop?
Pesticide sprays kill adult flies but are not necessary if you keep the coop clean. They also kill beneficial insects and can leave residue on surfaces where chickens peck. If you choose to spray, use products labeled safe for poultry areas and follow directions carefully. Most experienced chicken keepers find that cleaning and removing wet bedding works better and costs less.
Do I need to treat the coop in winter?
Fly activity drops dramatically in cold weather, so winter fly problems are rare. If you live in a warm climate where flies breed year-round, the same practices explore: keep bedding dry, store feed in sealed containers, and drain standing water. In cold climates, you can relax cleaning frequency in winter but should resume regular schedules in spring.
What if my coop is too wet to dry out?
If the ground around the coop stays soggy even after rain, you need to improve drainage. Dig a shallow trench to direct water away from the coop, or build the coop on a slight slope. You can also add sand or gravel around the base to absorb water. If the coop itself is in a low spot, moving it to higher ground is the most effective long-term solution.