Robber flies are impressive predators that typically specialize in flying insects, including wasps, bees, and dragonflies; the prey may be larger than the robber fly itself. Most robber flies frequent sunny, open areas and are active during the warmest parts of the day and year. They perch on branches, logs, stones, or the ground, and rush out to attack when suitable prey flies by. The robber fly uses its bristly legs to intercept the prey by grasping it around the head or back. Then, employing its needlelike mouthparts, the robber fly stabs the prey and injects a saliva that contains nerve toxins and digestive enzymes. This quickly paralyzes the prey and liquefies its tissues; the robber fly then sucks out the prey’s insides, much as spiders do. Some robber flies closely resemble certain species of bumblebees. This may provide the flies with protection against potential predators, and it may enable the robber flies to more easily approach and attack the bees themselves.