We are all familiar with the house fly, which feeds on decaying organic matter (among other disgusting things), and is pretty much harmless to other insects. However, there are around 120,000 species of flies in the world (many are yet to be discovered) and some of them are accomplished predators. Robber flies are among these; they have extremely sharp eyesight and can fly at high speed, catching other insects in mid air. They have stabbing mouthparts (proboscis) which inject a powerful neurotoxic venom and digestive juices into the victim, liquifying its innards, which the fly sucks afterwards. Due to this formidable weapon and the robber fly’s devastating attack speed, not even wasps, bees or spiders in their webs are safe from these aerial killers. Robber fly venom is usually harmless to humans, but if captured they can give an extremely painful bite.