The cannibal mosquitoes in the genus Toxorhynchites are large and conspicuous, but they do not bite humans. The larvae of these mosquitoes eat the larvae of other mosquito species. As adults, the Toxorhynchites feed exclusively on nectar and other plant juices. The eggs may be laid singly or in rafts but always in association with water and where it is quiet and protected. Females may lay up to 100 or 200 eggs per batch and deposit an egg batch every 7 or 10 days.
Eggs can take from days to months to hatch.
In general, during warm periods and under favorable conditions, eggs will hatch in a few days. Eggs may be laid at the water surface, at the water-soil interface along banks, or on soil or vegetation that is subject to periodic flooding, depending on the species involved. Other sites where eggs may be deposited include tree holes, temporary puddles, freshwater and salt marshes, and containers in which water stands, such as discarded tires, cans, pet water dishes, and bird baths. The larvae have no legs and have an enlarged thorax that is much wider than the head and abdomen. They feed on decaying organic matter that includes microorganisms.