Many mosquito species are most active at night, or at dawn and dusk, primarily to avoid the dehydrating effects of sunlight. Direct sun exposure can be lethal to these insects. While some mosquitoes bite during the day, the common house mosquito and many others actively seek shade and damp areas during daylight hours, becoming more active once the sun sets and temperatures cool.
Mosquito Activity and Time of Day
- Sun Avoidance: The primary reason mosquitoes are more prevalent at night is to avoid dehydration and death caused by direct sunlight.
- Temperature Preference: Cooler temperatures at dawn, dusk, and night are more favorable for their activity.
- Host Activity: Humans and other warm-blooded animals are often more active at night, providing more potential blood meal sources. This is especially true during the warmer months.
- Species Variation: It's important to note that not all mosquito species exhibit the same behavior. Some species are diurnal (active during the day), while others are nocturnal (active at night), and still others are crepuscular (active at dawn and dusk).
While some sources state that mosquitoes are "not active at night so much as avoiding the sun during the day," this is a simplification. They are more active during cooler, darker times, taking advantage of favorable conditions and increased opportunities to feed. Artificial lights can also extend their nighttime activity.
The CDC confirms that mosquitoes can bite day and night, but the preference for cooler, darker hours is consistent across numerous sources. The increased incidence of bites during the evening and night is largely due to the combination of factors outlined above.
