How do I get rid of a fly infestation?

Question

There are 2 rooms in my house with hundreds of flies that regenerate every day. Fist off, is the batthroom. I don't know where they could be coming from, and I can't find maggots everywhere. There'll be like 20 full grown flies and countless babies on the mirror, and I'll kill them, and close the door. 1 hour later, I'll come back, and there they'll be again! Even though the door's closed.

The other place is our sliding glass door in our living room. Every morning, there's literally a couple hundred baby flies crawling on the window. No matter how many I kill, they come back. I tried fly paper but it doesn't work. I can't find maggots anywhere, and there's no food left out anywhere. We even have maids come every week to clean the house.

So what's going on? We've always had our fair share of ants, but never with flies like this! Can someone help?

Answer 1

I am infested with flies every spring. I started using Ortho Home Defense Max. I spray inside and out and it helps. I got a 2 gallon spray jug at Sam's Club for $20.

Answer 2

I had a smiliar problem with flying ants.  They would all gather in front of the window, because they are attracted to the light.  I had never had them before so called Pest Control.  I was told that they were nesting under the fireplace hearth and during the day would move toward the light, then back under the hearth at night.  Pest Control sprayed and had to return for about three days before they all died/left.  I do know that when insects swarm like this, it is for a limitied amount of time, then they move on to find a new place.