Natural History Food Larvae eat many things. They graze over rocks and plant material removing growing algae and bacteria. They will filter feed from polluted water, but the water in which they live must never be allowed to develop a scum as they must be able to contact the air through the siphon at the end of the abdomen. Both male and female adults feed on nectar. Females also feed on blood which is needed to produce eggs.
Some species can produce eggs without a blood meal.
Males do not feed on blood. Habitat Larvae and pupae live in water, usually still water. They do not survive well in rushing streams or badly polluted water. Adults hide in vegetation near water or in cool, damp places. Many species fly in search of blood meals in the evening.