In a nutshell, cicada killer wasps don’t sting unless provoked or mishandled. But, even though they’re generally harmless to people, they’re still unwanted because they cause damage to gardens and lawns. Here are a few things you should know about these insects: Appearance and Habitat Cicada killers are quite large, and adult males and females can reach up to 1.5 to 2 inches in length. They have black or dark brown ...