Some types of mosquito lay their eggs on the surface of the water, fresh or stagnant, and some types lay their eggs on damp soil that will be flooded. Mosquito eggs float on the surface of water either singularly or as part of a raft as pictured above. Most species of mosquito lay eggs that hatch within 48 hours but some species.

Larva-

The eggs hatch in larvae which live in the water from 4 to 14 days. Larvae need to breathe oxygen and therefore hang upside down at the surface of the water so that they can breathe using a breathing tube called a siphon. They have brushes at their mouth to filter in food such as algae, plankton and other microorganisms. They shed their skin four times and during the fourth molt they turn in a pupa.

larva hatching from egg taken from taken from http://www-rci.rutgers.edu/~insects/mosvid.htm

Pupa-

When in its pupa stage a mosquito does not eat. Pupae are lighter than water and therefore rest on the surface. The pupae's defence mechanism is a tail which can propel it to the depths of the water if it is disturbed. After 1 to 4 days the pupa begins the transformation into an adult mosquito in a pupa case. This metamorphosis is similar to that of a caterpillar when it transforms into a butterfly. Once the fully formed mosquito leaves the case it rests on the waters surface until its body dries and hardens.

adult mosquito emerging from pupa case taken from taken from http://www-rci.rutgers.edu/~insects/mosvid.htm

Adult-

Adult mosquitoes cannot fly until their body has hardened properly and their wings are dry. Although the female mosquitoes drink blood for the most part both male and female mosquitoes feed mainly on nectar. Females require the protein found in blood to produce eggs and it may not feel like it sometimes but humans aren't the preferred choice for a meal.