Did the azalea get treated with a foliar spray for fertilization? Also check for scat under the bush. Perhaps an animal sprayed or marked nearby.

Some flying insect sprays claim on the can to kill for weeks, perhaps using that would discourage the flies. The stuff I use smells quite nice.

No, I'm an organic gardener and the only product i use is Neptune Fish/Seaweed emulsion. It's a water based fertilizer, which I've only used on those bushes once this year, about a month ago. And the flies were there long before that.

The shrub is in the foundation next to the front door. I will check to see if there is anything from an animal, but the animal would have to keep doing it repeatedly for the flies to be here from April to August, no?

Well…thank you for taking a shot at it and I'll take a closer look around the base of those shrubs in the area.

If they look like houseflies but perhaps a little bit smaller, they could be the Lesser Housefly, Fannia spp. The behavior of your flies, hanging around a shrub near the home, is typical of the Lesser Housefly.

It is the Lesser that is apt to try to overwinter inside, by the way.

Here's the thing......the only successful way to eliminate any kind of housefly is to get rid of their breeding areas. Garbage, especially soupy rotting garbage, and animal manure (fresh) is where they breed. Period.

This environment may not be at your backdoor, but probably not too awfully far away.

The adults feed on our food, sweet stuff, they may hover around insects that produce honeydew. Check your azalea for scale insects.

No, there is no garbage or anything rotting anywhere in the area, not on my property or anyone else's that I can see. I'll check for scale insects…thanks.

I would be curious to know if they roost there overnight.

BTW - I didn't notice this year if I had the flies, but - I definitely had scale on the shrub next to it. Planning to get rid of the holly that was covered with scale. I didn't notice if the azalea had it too. I'll have to check it.