Many hoverfly species mimic wasp colouration to avoid attack by birds and other predators. This is an example of Batesian mimicry, where harmless species mimic dangerous species, gaining protection from visually searching natural enemies. Over 250 species have been recorded in the UK, and more than 85 species have been found in a single garden. Hoverfly adults are generally seen on the wing between March and early November. While the adult hoverfly mainly feeds on nectar and pollen, the larvae of many species are voracious predators of aphids and other garden pests. As a result, hoverflies should be welcome in any garden, acting both as efficient pollinators and pest controllers. The female hoverfly requires pollen and nectar to mature her eggs, and then uses aphid honeydew as a cue to locate aphid colonies.
Hoverflies can fly in bursts of up to 40km per hour.
The rat-tailed maggot is the larva of a hoverfly species, the drone fly Eristalis tenax. It lives in foetid habitats such as stagnant water, sewage and farmyard manure. To compensate for the low oxygen levels in these environments it breathes through its tail, using it like a snorkel.
Hoverfly sexes can be separated by looking at their eyes - the male's eyes meet at the top of the head, whereas the female's eyes are separated by a gap.