My cat has taken to sitting on the table right in front of the rat cage, and I've noticed a lot of sniffing type noises, especially from one guy, while the cat is sitting there. Also, the same guy seems to be lunging at the cat, sort of trying to get him or something.

Could the noises be some sort of aggression noise? Or could he really be allergic, and just sneezing while the cat is there? I haven't noticed a lot of sneezing other times. Hmmm.