Here is how you can tell if you have encountered a stinging insect or a hover fly. All you have to do is remember this brief saying, “Two wings fun, four wings run.” In other words, flower flies possess only one pair of wings, whereas yellowjackets and their relatives have two sets of wings. In addition, while the flower fly will not sting or bite, as we all know, bees, yellowjackets, wasps, and their kin are armed with a stinger that they will use to inflict a painful sting.