Is it possible that the flies are entering the house through the cold air returns and/or the heating/air conditioning vents?? We have a crawlspace for the basement and have determined that's where Chipmunks live. If the flies can enter through our vents, I plan to screen the backsides of those vents. I have found no other source of possible entry into our house.
Flies in the house every spring
pest-control
Related Solutions
I used a tall plastic bucket once to catch the mice in the garage - I just put a small amount of dog food in the bottom, they could not climb the walls or jump that high to get out. I used a "ramp" made of simple cardboard to the top so that they could hop right in! Safe, no poison and easy to carry out when "full".
There are plenty of recommendations out there on the web, but I can't say how well they work. I think the lifespan of a gnat is something along the lines of 15 days, so you basically just have to remove their food source, and they'll be gone in 2 weeks.
Clean dishes quickly, keep everything clean, get rid of potted plants (they feed on the manure found in many types of soil that you might get for potted plants) or cover the top layer of soil with an inch of sand to prevent them from getting to the manure, look for any dead animal bodies (rats, lizards, birds, etc.)
I've also seen ideas for traps, which supposedly work pretty well, but just because you catch some, that doesn't necessarily mean that you'll get rid of their breeding grounds. The basic idea is that you take a cup and put 1" of vinegar and one drop of dish soap in it, then cover it with something that resembles a funnel (curl up a piece of paper into a cone shape and cut the tip off.) They'll be able to fly in because the funnel will guide them downward, but they won't be able to get out so long as you seal between the lip of the glass and the funnel (maybe fold it back down on the outside of the glass and secure it with rubber bands. Like this:
Best Answer
We bought a house on a golf course in Colorado. After we moved in we found out we had plenty of flies, EVERY single day. The house is big but new (2003). WE asked pest control, they couldn't figure it out. Everyone around here was saying it's a problem with big homes!! In the meantime, my husband wanted to organize the garage so he hired a handyman to hang ladders and stuff on the wall of the garage. The handyman started drilling holes in the wall under a window but he couldn't find the studs. He pulled the wall and found that under that window (there is a porch above that window) all the wood was rotten but not wet. It turned out that there had been a leak on that porch and previous owners had replaced the porch, however, there were no signs of the water getting inside the walls, hence the rotten wood! So, we had the contractors replace the entire wall. Since then we have had no flies. Flies were getting in through that rotten wall. If my husband hadn't decided to rearrange the garage, we would have never gotten rid of those flies. I am not sure if this will help anyone but it sure is a strange way of finding out how flies get into a house.