Larvicides are chemicals or natural bacteria that can be applied to kill mosquito larvae.
Larvae are one of the four forms in a mosquito's development. Adult mosquitoes lay their eggs on surfaces of standing water and the larvae live and develop into pupae in the water. Larvicides can be applied to standing water as liquid, a spray, granules or briquets. A briquet is a block that is placed in the water where mosquitoes breed. The briquet releases concentrated larvicide slowly over weeks to months.