Mosquitoes are small, flying insects that are common throughout California. Mosquitoes bite and feed on the blood of animals and humans. After feeding on blood, a female mosquito will lay eggs on or near water. The young stages of a mosquito grow in standing water. There are more than 50 kinds of mosquitoes in California – not all are a threat to humans, but several kinds bite and attack humans, and some can spread diseases (such as West Nile virus) when they bite. ​

The best way to prevent diseases that are spread by mosquitoes i​s to protect yourself from mosquito bites: use mosquito repellent on clothes and exposed skin when going outdoors (especially at dawn and dusk), and wear long sleeves and pants for extra protection. You can also keep biting mosquitoes from breeding near your home by draining standing water around your yard.