How to Keep Flies Out of Your Chicken Coop

Every chicken keeper in Texas knows the moment. It's a warm morning after a rain, you open the henhouse door, and a cloud of flies gets up to say hello.

Here's the good news: flies aren't a sign that you keep chickens. They're a sign that something around the coop is wet. Find the wet spots and keep them dry, and you can win this fight without spraying anything.

Know your enemy: a fly's week

Most of the flies around a coop are house flies. Their trick is speed. In summer heat, a house fly goes from egg to egg-laying adult in about 7 to 10 days, and each female can lay around 500 eggs over her short life.

Look at where those eggs go: wet droppings, spilled feed and damp bedding. Maggots need moisture to grow. Dry, crumbly droppings are a poor nursery, and most of the eggs laid in them never make it.

That gives you two simple rules:

1. Keep things dry, so flies have nowhere to lay eggs.
2. Clean out at least once a week, so any maggots that do hatch get hauled off before they turn into flies.

If you only remember one thing from this post, make it that second rule. A weekly clean-out lines up with the fly's life cycle and breaks it every single time.

The fly that bites your ankles is a cousin, the stable fly. It breeds in wet, rotting hay, straw and spilled feed, so the same fixes work on it too.

Where flies get started

Flies don't spread out evenly. They breed in a handful of predictable spots, and once you know them you'll see them around every coop.

Let's take them one at a time.

1. Under the roost

Chickens do a lot of their business at night, so the ground under the roost bars collects more droppings than anywhere else in the coop. That pile is fly headquarters.

The easiest fix is a droppings board: a shelf under the roost that catches the night's droppings so you can scrape them off in a minute or two. Do it every day or two in summer and the flies never get a start.

Our sliding poop shelf slides out to empty, so you aren't crouched in the henhouse with a scraper. It comes standard on the Modern Farmhouse, and you can add it to most of our other coops.

2. Under the feeder

Chickens are messy eaters. They flick feed out of the feeder looking for the good bits, and once that feed gets wet it sours and starts to smell, which flies love.

• Hang the feeder at about the height of your hens' backs, so they can't scratch feed out of it.
• Pick a feeder with a lip or a no-waste design.
• Feed kitchen scraps only in amounts the flock finishes in about 15 minutes, and rake up anything left over the same day. A watermelon rind left in the run overnight is basically a fly hatchery.

3. Around the waterer

An open waterer gets kicked, tipped and splashed, and the ground under it turns into black mud that never dries. That mud mixed with droppings is perfect for maggots.

Nipple or cup waterers like this one keep water in the bucket, not on the ground. If you still get a wet spot, set the waterer on a few pavers or a bed of gravel so splashes drain away.

4. Low spots that hold rain

If rain pools in a corner of your run and sits there for days, flies will find it. A few fixes, from easiest to biggest:

• Fill the low spot with sand or gravel. Sand dries fast, and you can sift droppings out of it with a rake.
• Add gutters to the coop roof so roof runoff goes somewhere else instead of into the run.
• Set the henhouse on a raised floor so it stays dry even when the yard floods.
• When you're choosing a spot for a new coop, pick high ground that drains. It's the cheapest fly control there is.

5. The manure pile

Chicken manure is great for the garden, but an open, damp pile next to the coop raises flies for the whole yard. Move the pile well away from the coop, and from your back door. Cover each new load with a layer of dry leaves, straw or wood shavings. A compost pile that's built right and turned so it heats up will cook fly eggs and maggots. A cold, soggy heap won't.

Let the air move

Still, humid air keeps litter damp, and damp litter breeds flies. Good airflow dries everything out, and it keeps your hens more comfortable in a Texas August too.

Make sure your henhouse has vents up high, where hot, wet air collects. If your coop runs hot or damp, a solar ventilation fan pulls that air out with no wiring needed.

Bring in some help

Once the wet spots are handled, a few helpers can mop up the rest.

Your chickens. Hens are excellent fly hunters. They'll chase flies down and dig maggots out of the ground all day long. They won't fix a dirty coop on their own, but they're a big help in a clean one. If you keep a chicken tractor, moving it to fresh grass every few days spreads the droppings thin, so they dry before flies can use them.

Fly predators. These are tiny wasps, about the size of a gnat, that lay their eggs inside fly pupae and stop the next generation from ever hatching. They don't sting people and they won't bother your flock. You order them by mail and release them near the trouble spots every few weeks through the warm months. They work slowly and they work best around a clean coop, but they keep working all season.

Traps, placed smartly. Bait traps work by smelling terrible to people and wonderful to flies. Hang them away from the coop and your house, so they pull flies away from both. Sticky fly strips work inside the henhouse, but hang them up high where no hen can reach them, because a chicken stuck to fly tape is a bad day for everyone.

What about sprays, powders and herbs?

You'll see a lot of other advice online. Here's our honest take.

• Insecticide sprays: if you use any, read the label and use only products labeled for poultry and poultry houses. Keep them off feed, water and nest boxes, and follow any wait time before eating the eggs. A spray only kills the flies that are already there. The next batch is already growing in whatever is still wet.
• Diatomaceous earth: it gets recommended a lot, but the research on it for fly control is mixed. The fine dust isn't good to breathe, for you or your hens, so go easy if you try it.
• Herbs like mint, lavender and basil: they smell nice and the hens may enjoy them, but there's little evidence they keep flies away. Plant them because you like them, not as your fly plan.

A simple weekly routine

Flies boom in Central Texas from the first warm spell in spring until well into fall, and especially after rain followed by heat. During fly season, this routine keeps most coops in good shape:

• Every day or two: scrape the droppings board, pick up leftover scraps, and check the waterer for leaks.
• Every week: clean out wet litter, especially under the roost, feeder and waterer. Rake the run and fill any low spot that's holding water.
• After a big rain: walk the run and the manure pile, and dry out or cover anything that got soaked.
• Every few weeks: release fly predators if you use them, and move or empty your fly traps.

If a fly problem shows up suddenly, look for the one wet spot you missed. There's almost always one.

Building a coop that's easy to keep clean

The less time it takes to clean a coop, the more often it gets done, and that's what really beats flies. When we design our coops, we think about the chore list:

• A sliding poop shelf under the roost, or our Easy Clean Combo, which adds a removable roost and an angled nest-box cover so hens can't roost or poop on top of the nests.
• A raised, treated floor that stays dry when it rains.
• Gutters to keep roof water out of the run.
• A solar fan and windows for airflow.
• A no-waste feeder and auto waterer to cut down on spilled feed and splashes.

Have a look at our walk-in chicken coops and the add-ons we offer, or build your own and ask us for a quote. Have a fly question we didn't cover? Send it our way. We're always happy to talk chickens.