Hesperian Health Guides
Prevent Mosquitoes From Breeding
Different kinds of mosquitoes breed in different kinds of water. Killing adult mosquitoes stops both their bite and their breeding, but killing the eggs or larvae that hatch in water, or taking away the water needed for mosquitoes to hatch the eggs, is most effective.
The mosquitoes that spread dengue, yellow fever, Zika, and chikungunya breed in clean standing water. If the mosquitoes find water, they lay eggs. After 2 days, the eggs hatch into larvae that live under the water surface. After 4 more days, the larvae begin to turn into mosquitoes with wings. In 2 more days, they can fly away. By getting rid of standing water once a week, mosquito breeding is interrupted because the eggs do not hatch.
The mosquitoes that spread malaria also lay eggs in water—sometimes in small amounts of fresh water in or near the home like the dengue mosquito but also in larger bodies of water that cannot be emptied out or filled in. If there are any kinds of mosquitoes in or near your house, it is always a good idea to take away, empty out, or tightly cover places where water collects or is stored.
Remove mosquito breeding sites around the house and community
Outside the home: get rid of places where water collects such as old car tires, flower pots, oil drums, ditches, small plastic containers or toys and even bottle caps. Do this at least once a week. A sloped roof and a system that captures water that otherwise would form pools on the roof or the ground helps stop mosquito breeding. Fill holes in trees where water collects and fill in hollow fencing, especially bamboo.
Communities use many different materials to make mosquito traps that attract and kill mosquitoes and their eggs. One type of trap uses pieces of old tires that need to be cleared anyway for mosquito prevention.
Inside the home: Change the water in water dishes for animals and flower vases at least once a week. Unless containers are scrubbed clean, mosquito eggs can stick to the sides of the containers where they can live for months until there is water to make them hatch.
Outside and inside the home: Always tightly cover water storage containers so mosquitoes cannot get inside to lay eggs. If any eggs were laid, the cover will prevent hatched mosquitoes from flying away. If there are holes or gaps, the cover won’t work. For containers, barrels, or water tanks with no lids, use screens or wire mesh with holes too small for a mosquito to enter, or cover with fabric that water will pass through and tie in place. Or use plastic lids that seal tightly. Make sure that rain cannot collect on top of the cover or mosquitoes will lay their eggs there!
Manage waterways and drain runoff from wells and taps
Where there is malaria, roadways and anywhere else water collects need attention to stop mosquitoes from breeding. Keeping natural waterways and rain water moving and flowing will keep water from collecting. Manage land so water soaks into the ground or runs off into streams. Clear streams blocked by eroded soil, leaves, or other debris. Hesperian’s Community Guide to Environmental Health has more information on how to manage water and choose toilets and latrines that avoid pits of waste water.
Wherever people collect water, water spills. When water collects in puddles, it becomes a breeding ground for mosquitoes that carry malaria and other illnesses. Wells, taps, outlets from storage tanks, and other water collection areas need good drainage to allow spilled water to flow away or to drain into the ground.
To take advantage of water that runs off, plant a tree or a vegetable garden where the water drains. If you cannot plant a tree or garden, make a hollow in the ground filled with rocks, gravel, and sand for the water to seep into. This is called a “soak pit.” It will help prevent mosquitoes from breeding.
See if there are successful programs in your region using fish that eat mosquito larvae in ponds and lakes. Or find out if the bacteria called Bti is available because it can be used successfully to kill young mosquitoes before they breed and does not harm the environment.