Bug Identifier

Flies & Mosquitoes

House Fly

Musca domestica

0246810
Body length in millimeters. Shaded bar shows the typical adult range.
Scientific nameMusca domestica
GroupFlies & Mosquitoes
Size6–7 mm (up to about 0.28 in)
Colors Gray and Black
Legs6 legs
WingsYes
Where foundKitchen and Indoors, anywhere
Most activeSpring, Summer and Fall
BitesNo
StingsNo
Risk levelNuisance

How to identify it

The house fly is a small member of the flies & mosquitoes group. Only one pair of flying wings; the hind pair is reduced to tiny knobs. Check for these three features:

  1. Four dark lengthwise stripes on a gray thorax
  2. Red compound eyes
  3. Sponging mouthparts that cannot bite

About this bug

The most common fly in homes, a dull gray fly with four dark stripes on its thorax. It breeds in garbage, manure and rotting food and lands on nearly everything.

You'll usually find house flies in the kitchen and indoors. They are most active in spring, summer and fall.

Is it dangerous?

House flies don't bite, but they can carry bacteria that cause food poisoning.

Our rating: Nuisance, meaning it is a nuisance pest but not a health threat to most people.

When you'll see house flies

House Flies are most active in spring, summer and fall. In spring, overwintering adults become active and many species lay their first eggs. Summer heat speeds up development, so populations can grow quickly. In fall, many bugs look for shelter, and some move toward or into buildings.

Typical places to check: kitchen and indoors, anywhere.

About flies & mosquitoes

The house fly is one of the flies & mosquitoes. Flies have only one pair of working wings; the second pair is reduced to small balancing knobs called halteres. They go through complete metamorphosis, and the larvae, called maggots, need moist organic material such as garbage, soil, drain film or standing water.

Fly problems are almost always breeding-site problems. Finding and removing the moist material where larvae develop works far better than swatting adults.

What to do about it

  1. Keep trash tightly covered and take it out often
  2. Repair window and door screens
  3. Use fly traps or sticky strips away from food areas

Read the full guide: how to get rid of house flies.

Bugs that look similar

Blow FlyLucilia sericata8–12 mmNuisance

Size: Blow Flies are larger, reaching 12 mm, while house flies top out around 7 mm.

Horse FlyTabanus spp.10–30 mmCan bite or sting

Size: Horse Flies are larger, reaching 30 mm, while house flies top out around 7 mm.

Frequently asked questions

What does a house fly look like?

Four dark lengthwise stripes on a gray thorax. Adults measure 6–7 mm (up to about 0.28 in).

Does the house fly bite or sting?

It does not bite. It does not sting. House flies don't bite, but they can carry bacteria that cause food poisoning.

Where do house flies live?

House Flies live in the kitchen and indoors.

When are house flies most active?

Mostly in spring, summer and fall.