When I was a little kid, my older sister used to bite me sometimes. My mom once told her in front of me when I was about 4, that if she did it again, my mother would bite her back. As soon as my mom was elsewhere, I bit the outside of my forearm hard enough to leave a mark that looked like someone else had done it (I know, younger siblings, but she was ten years old biting a preschooler, so I support it). My mom did bite her, but probably not really very hard and my sister stopped biting me after that. I’m not sure how I feel about that parenting, but I’m not a parent, so I’ll withhold judgement. Plus it worked.

I’m pretty sure they’ve both been around forever