[Aquattro]

Tony, a full grown mantis (12"+) has the impact of a 22 cal. at muzzle velocity. Which means they'd take off your finger very easily. It is recommended that they be housed in acrylic tanks when they're larger, because they can and have broken thru glass. Good idea not to tease one thru the glass!!
One of mine is a spearer variety and has smashed a small condo in a chunk of rock. The hole used to be the size of a pencil, about 3" deep. I could probably fit a couple of golf balls in there now.
Any one of mine can easily cut a hermit clean in half with a couple of smacks.
Darren's is probably three times the size of my largest. I wouldn't have my fingers anywhere near it.