Common Bat Fly vs Speyer's Cave Beetle

Side-by-side species comparison

Attribute Common Bat Fly Speyer's Cave Beetle
Scientific Name Basilia nana Aphaobius milleri
Order Diptera Coleoptera
Family Nycteribiidae Leiodidae
Size 2-3 mm 3-5 mm
Habitat Caves Caves
Diet Blood Feeders Detritivores
Regions Europe Austria, Slovenia
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.

Speyer's Cave Beetle

A troglobitic beetle endemic to caves in the eastern Alps. It has a convex body shape and completely lacks eyes.

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Did You Know?

It can tolerate near-freezing temperatures in high-altitude caves.