Rats do best when they are kept separate from other pets. Dogs, cats and large birds can pose a danger to rats, and should never be trusted near your rat. Dogs and cats shouldn’t be allowed to hang around a rat’s cage because it may stress the rat. Parrots that make screeching noises should also be kept in a different room from your rat.
Rats can live in the same room with rabbits and guinea pigs, but all should be housed in separate cages.