If your mantis is male then generally you don't have to worry about it. Males are way less aggressive than females are.I used to have a female Chinese mantis who was EXTREMELY aggressive. I would always wear hoodies and pull my arm inside to hold her. :lol: She would attack the cloth sometimes but never hurt me.
Usually, attacks happen when you're holding an aggressive mantis and they see your finger twitch. I've had that happen before and my female attacked my finger. It didn't hurt a lot, but it delivered quite a pinch. If that happens I usually place my finger under the neck of the mantis and hold him or her back to prevent them from biting me until I get my trusty water sprayer.