Insect identifier · Mosquitoes
How to identify a Northern house mosquito
Culex pipiens
· Also called culex, house mosquito, culex pipiens, night mosquito in house, west nile mosquito

Night bites indoors in northern cities are often Culex pipiens, the northern house mosquito — a plain brown mosquito, not a tiger mosquito.
Someone searching this page usually has a northern house mosquito in a photo, on skin, or in a story about storm drains, birdbaths, indoors. Use the marks, the bite, and the range together. Night bites indoors in northern cities are often Culex pipiens, the northern house mosquito — a plain brown mosquito, not a tiger mosquito.
What does a northern house mosquito look like?
Plain brown, no flashy stripes, rounded abdomen. It breeds in stagnant, sometimes dirty water: storm drains, neglected birdbaths, clogged gutters. It may overwinter in basements.
Northern house mosquito (Culex pipiens) is Small–medium, about 4–10 mm. Colors people notice: brown, tan. Field marks: Plain brown, no flashy stripes; Rounded abdomen; Night biter, often indoors; Breeds in stagnant, sometimes dirty water. It is found both. If those marks are missing, open Western encephalitis mosquito, Inland floodwater mosquito before you force this name. Search phrases that belong on this page include what a northern house mosquito looks like and northern house mosquito identification.
Identification marks
- Plain brown, no flashy stripes
- Rounded abdomen
- Night biter, often indoors
- Breeds in stagnant, sometimes dirty water
Size: Small–medium, about 4–10 mm
Colors: brown, tan
Where: both
What a typical northern house mosquito bite looks like

A few itchy bumps noticed overnight on arms or face after sleeping near an open window. Culex species are the main West Nile vectors in North America; most bites do not transmit disease, but summer fever still needs a clinician.
People searching “northern house mosquito bite identification” want the pattern, not a single anonymous bump. Itchy bump that may appear overnight. Often a few bites on arms or face after sleeping near an open window. Immediate steps on this page: Soothe the itch; check window screens; If you have fever or neurologic symptoms in summer, seek care (West Nile risk is low but real); Empty birdbaths and clogged gutters. This species does bite or sting people. Fever, spreading redness, trouble breathing, or a child with many stings is professional care.
If you were bitten
- Soothe the itch; check window screens
- If you have fever or neurologic symptoms in summer, seek care (West Nile risk is low but real)
- Empty birdbaths and clogged gutters
Northern house mosquito vs Western encephalitis mosquito
No stripes. Night. Indoors. That triad separates Culex pipiens from tiger mosquitoes. Anopheles rest tail-up. If you are bitten in bed in a northern city in July, think house mosquito or bed bug — the mosquito is a few scattered welts, not a breakfast-lunch-dinner line.
- Western encephalitis mosquito identification (Culex tarsalis)
- Inland floodwater mosquito identification (Aedes vexans)
- Yellow fever mosquito identification (Aedes aegypti)
- Common malaria mosquito identification (Anopheles quadrimaculatus)
- Cattail mosquito identification (Coquillettidia perturbans)
- Black fly identification (Simulium spp.)
- No-see-um identification (Culicoides spp.)
- Bed bug identification (Cimex lectularius)
- Southern house mosquito identification (Culex quinquefasciatus)
- Crane fly identification (Tipula spp.)
- Mayfly identification (Ephemeroptera)
- Caddisfly identification (Trichoptera)
Range and season
Common across the northern U.S. and southern Canada. Summer nights.
Northern cities and suburbs, basements, storm drains, and rooms with open windows after dark.
Common across the northern U.S. and southern Canada. A Culex relative (C. quinquefasciatus) replaces it in the deep South.
Summer nights; may overwinter in basements
Common questions
Does the northern house mosquito carry West Nile virus?
Culex species are the main West Nile vectors in North America. Most bites do not transmit disease, but prevention still matters.
Why do I get bitten at night in the house?
Culex often rest indoors and bite after dark. Check screens, door gaps, and basement windows.
What does it look like?
A plain brown mosquito without tiger stripes. Identification to species usually needs a close look at the abdomen and legs.
What mosquito bites at night in the house?
Culex house mosquitoes. They are plain brown, rest indoors, and bite after dark near open windows.
What mosquito bites at night indoors?
Culex house mosquitoes. They rest indoors and bite after dark.
Does the northern house mosquito carry West Nile?
Culex species are the main West Nile vectors in North America. Most bites do not transmit virus.
Related identification pages
- Western encephalitis mosquito identification
- Inland floodwater mosquito identification
- Yellow fever mosquito identification
- Common malaria mosquito identification
- Cattail mosquito identification
- Black fly identification
- No-see-um identification
- Bed bug identification
- Southern house mosquito identification
- Crane fly identification
- Mayfly identification
- Caddisfly identification
- Asian tiger mosquito identification
- Gallinipper identification
- Woodland pool mosquito identification
- Saltmarsh mosquito identification
- All insect identification pages
- Identify an insect from a photo
