When do malaria mosquitoes bite humans?

Easy: When they are hungry, which is all the time. If you are in an area where malaria is endemic, take the appropriate prophylaxis, where repellent and sleep under repellent impregnated mesh.

Any time: The mosquitoes that cause malaria typically feed between dusk and dawn but they can bite at any time so use insect repellant that contains 20-40% deet or 10% Permethrin whenever you go out in a malaria endemic region.