Go very slowly and watch body language carefully. If you have an energetic puppy or a very large dog, be careful that your dog doesn't inadvertently hurt your rat - some dogs just aren't aware of their size and strength. Some dogs get very chummy with rats, licking them, following them around and watching out for them. Rats and rabbits Rats and rabbits seem to be a pretty good match - sometimes. They seem to speak the same language, but still you've got to be careful.
Aggressive rabbits can hurt a rat very easily, and aggressive rats can seriously annoy a rabbit.
If your rabbit can interact with your rats in an area where it can get away easily if it feels threatened, they should get on fine together. Rats are afraid of slithery snake-y things and will attack them, if they're not petrified with fear that is. Just thinking about this combo makes me shudder . This one is also not a good idea. I have heard of mice and rats who were raised together and get along wonderfully, but in general, rats see mice, gerbils, hamsters, etc. as prey and will kill them.