Fighting?

Hi Im pretty new to breeding rats. Im on my 5th litter all litters before were great and did perfect but this litter all babies are 5 weeks old and one of the babies has a mark above his eyes like someone bit him or something. Will brothers and sisters fight? I have never seen any of my rats fight each other but I wasnt sure if I needed to move him to his own tub

True fighting at that age would be uncommon. Once they get older, siblings can start fighting.

What is more likely is they were playing and it got out of hand. They bite and scratch in play and are still learning how hard they can do this and mistakes happen. Keep an eye on them and if you see any more wounds you may then need to move him and a sibling to a separate tub. I would never put a rat in an enclosure by itself, they are very social animals.

Good luck!