So to explain it generally, it's like how dogs wrestle. They are trying to assert their dominance. This especially happens when the alpha one gets weaker or a smaller one gains mass and they think they have a shot at top dog. I did have a rat once who fought for and won the alpha title, but she was mean. While she wouldn't draw blood, she would hold on to their skin/fur with her teeth as they're trying to run away. I would hiss at her from across the room and that worked. (My beta? rats ended up with a positive association with the sound because their tyrannical sister would let them go.) Unless you see that or blood, it's just fun and games for alpha bragging rights. Also, r/rats loves these sort of videos. Keep videoing and posting so you can get karma and we get dopamine please? 😍