Summer hit hard last weekend in Duluth, with temperatures climbing to the upper 80s or low 90s. To beat the heat, I mounted box fans in my windows and ran them over night when it was cooler. Because I live in an apartment, I set the fans to pull cool outside air in rather than push hot inside air out (which would have sucked hot hallway air in to replace it). About a half-hour after turning the fans on, I started noticing tiny flying insects in my apartment, especially gathering near lights.
These tiny insects turned out to be gall midges (family Cecidomyiidae). Gall midges are a diverse family; some species are major agricultural pests (e.g. Hessian fly), some species are beneficial (e.g. Aphidoletes), and most really have no effect on humans at all. They were small enough that the fan sucked them through the window screen and blew them into the apartment.
The gall midges were no cause for concern. They cannot infest buildings; their larvae are typically highly specialized to feed on very specific types of plants. Being tiny, slender, and relatively thin-skinned, they also dehydrate easily. The few that I noticed at night when the windows were open perished by the next day when I switched to air conditioning that removed the humidity from the air. These gall midges illustrate two important points: our homes are not insect-proof, but not all insects are pests. For more serious pests like rats, roaches, bed bugs, etc., Guardian will gladly help solve your problems. We will also let you know which insect neighbors are not problems at all.
Title picture photo credit: Sarefo, via Wikipedia