Annoyance factor: 6

Favorite hangouts: Moist areas around your home, plants, compost piles.

Most annoying when: You're taking advantage of some cooler temps to spend time in the garden.

Annoying, associated diseases and afflictions: Like their close relatives mosquitoes and no-see-ums, the super-annoying, nearly invisible family of flies known as gnats — a term often used as a catch-all for all pesky, small flies — can be vectors of infectious, sometimes dangerous diseases.

Repulsive eating habits: A common misconception is that all gnats can bite and are blood-suckers since they enjoy nothing more than swarming in your personal space. Depending on the type of gnat that you're dealing with it, some might rather feast on rotted fruits and vegetables, decaying wood and mushrooms. And then there are eye gnats, a type of small fly that feeds on eye secretions and other bodily fluids like pus, sebum and blood from humans and other animals.