Wasps

There are several species of common wasps native to Connecticut. Several of them are described here. The paper wasps(the one pictured above), and another which is shaped the same but is colored like a yellowjacket(called the Mediterranean Wasp). The Mud Dauber wasp is an dark iridescent bluish color. Wasps are very beneficial because they feed on caterpillars such as gypsy moth, and cabbage worm caterpillars. The mud dauber wasp feeds exclusively on spiders. Wasps in general are not particularly aggressive, but can be a problem if their nest is near a doorway, in a swing set for kids, etc.
There are dozens of uncommon wasp species including digger wasps, parasitic wasps, cicada killers, etc. I have included information about cicada killer wasps because they are very large, look terrifying as they fly over the surface of the ground above the burrows they dig in sandy soil, and although they are capable of stinging, they are essentially harmless.