What is a Mosquito?

Silhouette of a mosquito

Mosquitoes are common, flying insects that live in most parts of the world. Over 3,700 types of mosquitoes can be found worldwide.

Not all mosquitoes bite people or animals. When mosquitoes bite people, the most common reactions to the bite are itching and swelling.

Some mosquitoes can be vectors. A vector is an animal, insect, or tick that spreads pathogens (germs) to people and animals. The germs (viruses and parasites) that mosquitoes spread can make you sick.

Some mosquitoes bite, but do not spread germs. These types of mosquitoes are called nuisance mosquitoes.

Facts About Mosquitoes

Day and night
  • Adult mosquitoes live indoors and outdoors.
  • Mosquitoes can bite day and night.
  • Adult mosquitoes live for about 2 to 4 weeks depending on the species, humidity, temperature, and other factors. Female mosquitoes often live longer than male mosquitoes.
  • Only female mosquitoes bite people and animals to get a blood meal. Female mosquitoes need a blood meal to produce eggs.
  • Mosquitoes get infected with germs, such as viruses and parasites, when they bite infected people and animals.
  • It takes just a few infected mosquitoes to start an outbreak in a community and put you and your family at risk of becoming sick.

Parts of an Adult Mosquito

Stylized illustration of mosquito

Adult mosquito parts key


The head has many organs that help mosquitoes eat, see, and smell.

  • Antennae: Long feather-like organs that detect carbon dioxide from a person’s breath and movement of air.
  • Eye: Mosquitoes have two large compound eyes that detect movement.
  • Palps: Organs between the antennae that sense odor.
  • Proboscis: In female mosquitoes, this mouth part pierces the skin of a person or animal and sucks out blood. The male’s proboscis is not strong enough to pierce the skin, and males do not feed on blood. Both female and male mosquitoes use the proboscis to feed on flower nectar and fruit juices.


The thorax is connected to the head. Wings and legs are connected to the thorax.

  • Halter: A small wing-like organ used for steering while flying.
  • Wing: Mosquitoes have two wings used for flying.
  • Leg: Mosquitoes have six legs like other insects.
  • Femur: Upper part of the leg.
  • Tibia: Middle part of the leg.
  • Tarsus: End of the leg that helps mosquitoes stand and walk on water.


The abdomen connects to the thorax and serves as the stomach, reproductive system, and part of the respiratory system.

Genitalia: Where eggs are released from the female.