a chicken house is called a coop. look up chickens in coup, I don't think you want chickens living in your coup
How do I get rid of flies ? - Page 2
We use BARN lime under their pine shavings bedding and in the run. A 50lbs. bag is only about $3.00 or less. Please ensure it is BARN lime, other types are caustic and can "burn" your chickens. This also "cuts down" on that heavy ammonia smell produced by their droppings.
Here is a "sample" of the one we use, sold by TSC.
Permethrin 10% spray will help for 30 days in controlling insects, mites, and lice in the coop when applied to walls and floor. Very safe for chickens, but not if you have bees. I would also recommend stirring the pine bedding daily or have the chickens do it by throwing a bit of corn or scratch out. If you can smell chicken poop or ammonia, then it is probably time to clean and put new bedding down.