Robber flies are among the few insects that catch their prey in mid-flight. An individual establishes a perch zone. From there, it swoops out to snatch the unsuspecting victim that is often larger than its aggressor and may even include spiders, large predatory insects, and, sometimes, other robber flies. Robber flies range in length to almost 8 cm (3 inches), making them the largest of all flies. Most are dull in colour, and their stout, often hairy, bodies resemble those of bumble bees. Between the large-faceted eyes is a moustache of bristles.
