For our youngest it was headbutting, both of which are fairly normal behaviors for little kids. He's 3 now and rarely headbutts anymore. Biting can be stressful though, our kids have had their fair share of being the target of a bite over the years. We've never had to be told our kids bit someone but I imagine its not fun to hear. They eventually grow out of it (most do anyway).

Were having similar success with potty training! Though pooping is lagging behind peeing sadly. I'd rather clean 100 pee pants then 1 poop pants any day.

We went to an arcade recently that had a motorcycle game that you ride, like this:

I put K2 in front and I did the driving while he just slammed the turbo button as fast as he could while holding on. It was a blast, we placed 1st by a mile lol. So similar vibes to your earth moving. Once these kids are coordinated enough to game, it's on.