Cicada Killers
The cicada killer wasp is a large wasp 1-11/2 inches long. Males do not sting but females can. They make hole in the ground where their eggs are laid. The developing larvae feeds off of cicadas supplied by the female. These holes can be numerous but the wasps is not a colonizing wasps each hole if from a single wasps.
Cicada killers are not aggressive but can sting. Their size usually scares people. Their activity is most visible in the spring of the year after the larvae develop and emerge from the nest they can be found in gardens feeding on pollen.