Well, I did another today.
This time it was 4 rats, Vincent, Bandit, Nemo and Edgar,
Vincent keeps bugging Nemo a lot, sometimes they just move away from each other and other times Vincent tries to chase Nemo. They got into another rat ball. Bandit typically just stays away from the other rats and hangs out by himself once in a while eating the plate of spaghetti sauce I leave out. Edgar is eager but mostly hides away and pops his head out once in a while.
Bandit and Nemo are generally fine with one another, never had an issue with those two together. They even ate from the same plate without anything happening. They've laid next to one another, and usually just avoid if they're face to face having a stand off.
I had to remove Vincent after about 45 minutes because it was getting a bit out of hand. He was going after Nemo and Bandit at this point. I waited until things were calm and they had a moment where he avoided the situation before ending it right there. After Vincent was removed things were better... Nemo found a spot to rest by himself, Bandit decided to eat and Edgar was going around trying to sniff Bandit mostly. Nothing really note worthy happened afterwards. I ended the intro about 1h 15 minutes I think.
I don't really know what to do with Vincent to be honest.