Last summer I was working in the garden when a cicada-killer with cicada in it's "claws" hit he smack on the face hard enough to leave a mark. It then proceeded to drag that cicada along the grass until it was dead. Fascinating.The big cicada killers that fly around real low in the yard are also pretty docile.
They are very agressive to the poor cicada though. Everybodys gotta eat!
TE