Common Bat Fly vs Great Pied Hoverfly

Side-by-side species comparison

Attribute Common Bat Fly Great Pied Hoverfly
Scientific Name Basilia nana Volucella bombylans
Order Diptera Diptera
Family Nycteribiidae Syrphidae
Size 2-3 mm 12-16 mm
Habitat Caves Heathland
Diet Blood Feeders Parasitoids
Regions Europe Europe, North America
Conservation Least Concern Least Concern

Common Bat Fly

A tiny, completely wingless spider-like fly that parasitizes bats. Its body is so highly modified for ectoparasitism that it bears almost no resemblance to a typical fly.

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Did You Know?

It has evolved to be so specialized that its head folds back over the thorax, and it walks like a spider through bat fur.

Great Pied Hoverfly

A furry hoverfly that exists in multiple colour forms, each mimicking a different bumblebee species. Larvae develop inside bumblebee nests.

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Did You Know?

Different colour forms mimic different bumblebee species, with some resembling red-tailed and others white-tailed bumblebees.