Cicada killer wasps are large, solitary, ground-dwelling, predatory wasps. They are so named because they hunt cicadas and provision their nests with them, after stinging and paralyzing them. Adults emerge in summer, typically beginning around late June or early July, and die off in September or October. They are present in a given area for 60 to 75 days, usually until mid-September. The large females are commonly seen skimming around lawns seeking good sites to dig burrows and searching for cicadas in trees and taller shrubs. The males are more often seen in groups, vigorously challenging one another for a position on the breeding aggregation from which they emerged, and generally investigate anything that moves or flies near them. It is not unusual to see two or three male wasps locked together in apparent mid-air combat, the aggregate adopting an erratic flight path until one of the wasps breaks away. The male wasp's aggressive behavior is similar to that of another robust insect of the area, the male carpenter bee. In both cases, while the males' vigorous territorial defense can be frightening and intimidating to human passersby, the males pose no danger whatsoever. Male cicada killers will only grapple with other insects, and cannot sting.