Robber fly (Diptera: Asilidae) in Värmland, Sweden. This large (2 cm long) fly mimics bumble bees but hardly needs to protect itself (except from birds). It catches flying insects such as flies and pierces their body easily. I once saw one catch a large queen horse ant (Camponotus Herculeus) in flight and kill her before landing about 2 meters from the attack point at 2 m height. The queen was returning from a mating flight. The piercing might have been lucky as the puncture was at the wing insertion point but some cuticle was broken. The robber fly apparently did not like the taste as it left the dead ant on the ground, or maybe I scared it away (but I thought it left voluntarily).

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Images © 1996 by John A. Byers, Chemical Ecology.