Last Friday my mom and I picked up a couple male rats from a rattery for my nephew for Easter. I've been taking care of them this week since the kid is with his mom instead of my brother this week and one of them has been sneezing almost constantly since we got him. He's 3 months old and a little more shy and less active than the other rat we got but still very friendly. He doesn't have any stuff around his eyes or a runny nose or anything. We are using Carefresh bedding.

My mom contacted the breeder and she is giving us the option of swaping it for another rat or telling us how to treat him ourselves. We still don't really know what's wrong with him though! I've grown kind of attached to both rats even though they're not mine and want to do what is best for him.

Any ideas about what could be wrong or what I should do about it? :<