Ah, summer in Houston — when the humidity hugs you tighter than your grandma at Thanksgiving and your air conditioner becomes your best friend. But if you start noticing tiny, fuzzy bugs fluttering near your vents, your HVAC system might be hosting some uninvited guests: drain flies. Also called moth flies or sewer gnats, these little pests thrive in warm, damp environments — and your A/C’s condensate drain line or drip pan is the perfect vacation spot.