Most species of Tarantula hawks are around 5 cm (2 inches) long, making it the largest type of wasp. They usually have a blue-black body and reddish-orange wings, but some have black wings. The color on their wings tells predators that they are dangerous (aposematism). They have long legs which have hooked claws that are used for grabbing their prey. The sting of a female Tarantula hawk can be as long as 7 mm long; the stinger is said to be the second most painful insect sting in the world.