Wasn't sure where to put this post but i decided it was a building problem. We have just moved into our new house. Most nights we are attacked by small flying insects. They are not flying ants, much smaller. maybe 2mm in length. The problem is they are so small that they can make there way through our insect screens, and then it is impossible to sleep with insects landing on you all night. They don't bite but drive me mad. I have thought about spraying the screens with surface spray, but then i think the air coming into the house will be infused with surface spray chemical. Help! Any ideas what they are and how to keep them out?