Wasps are members of the same insect order (Hymenoptera) that also includes ants, bees and sawflies. Wasps eat certain plant-destroying insects and flies. Some wasps sting repeatedly when they, or their nests, are disturbed,  which makes them a threat to people and their pets. Some wasp species, like yellowjackets, hornets and paper wasps, are social insects that live in colonies in the way that ants do.