Shoo Fly Don't Bother Me

I have a fly problem, at first it was the normal size house flys. I could handle those with a fly swatter. They seem to have died down.

Now it's these itsy bitsy flys. They resemble fruit flys but I don't have any fruit. They swarm in a large cloud over my kitchen counters and sink area. I've tried flying insect spray but for some reason it kills everything except these litle buggers. I don't know quite what else to do I've cleaned everything up, I didn't find any spoiling food or anything. And now they've moved to my bathrooms. All I can do is hope they live out their lives and die soon!