Mosquitoes have four distinct life stages, with the first three stages of Culiseta (egg-larva-pupa) being spent in the water. An adult female lays about 150-200 eggs in clusters called rafts, which float on the surface of the water until they hatch in about two days. The eggs hatch into larvae (wigglers), which then feed on small organic particles and microorganisms in the water. About 10 days are required for larval development. At the end of the larval stage, the mosquito molts and becomes the aquatic pupa (tumbler). The pupa is active only if disturbed, for this is the "resting" stage where the larval form is transformed into the adult. This takes about two days during which time feeding does not occur. When the transformation is completed, the new adult splits the pupal skin and emerges.

Larvae are found in a wide variety of standing water sources including creeks, fish ponds, abandoned swimming pools, stagnant and polluted waters, log ponds, reservoirs, snow pools, brackish water, horse troughs, artificial containers, and even discarded automobile tires. Under optimum conditions development from egg to adult takes about two to three weeks. However, all mosquito developmental times are dependent on the temperature and food values of the water in which they develop.

Females feed primarily on fowl and domestic animals but on occasion will bite humans. Due to the limited flight range of this mosquito, most breeding sites are located near the area of complaints. Males do not bite, but feed on nectar and plant juices. Culiseta incidens is primarily a domestic nuisance and in some regions is considered relatively unimportant as a human pest. Successful laboratory experimental transmission of St. Louis Encephalitis (SLE), Western Equine Encephalitis (WEE) and Japanese B Encephalitis (JBE) virus does indicate a potential medical importance for this mosquito.

Where breeding sites exist in standing or slow moving water, corrective action to permanently eliminate them by such means as filling, pumping, ditching or draining is recommended. Ornamental ponds and watering troughs are common sources. Often the cool weather mosquito may be controlled in a source by stocking mosquito fish (Gambusia affinis).

Mosquitoes are estimated to transmit disease to more than 70 million people annually in Africa, South America, Central America, Mexico and much of Asia with millions of resulting deaths. In Europe, Russia, Greenland, Canada, the United States, Australia, New Zealand, Japan and other temperate and developed countries, mosquito bites are now mostly an irritating nuisance; but still cause some deaths each year.

Historically, before mosquito transmitted diseases were brought under control, they caused tens of thousands of deaths in these countries and hundreds of thousands of infections.[16] Mosquitoes were shown to be the method by which yellow fever and malaria were transmitted from person to person by Walter Reed, William C. Gorgas and associates in the U.S. Army Medical Corps first in Cuba and then around the Panama Canal in the early 1900s. Since then other diseases have been shown to be transmitted the same way.