Many times this summer when I've had the A/C on (and the windows closed, of course), I've noticed flies in the house. I'm a neat person, so it's not like I live in filth.

I assume they must be getting in (or sucked in?) near an A/C hose outside and coming up through a vent. Anybody else ever been in this situation?

Whom should I be calling to look at this? An A/C maintenance person or an exterminator? I'm thinking the latter might be able to spot how they're coming in but might not do the patching or whatever repair is needed.