Can I put different breeds of rats together?
Soft furred rats are not technically rats. If I remember correctly, I read that they are closer related to mice than actual rats. They certainly aren’t just a different breed, but an entirely different species. You may as well be comparing a guinea pig and rat to say the least. Now brown rats in the wild have been known to attack, kill, and eat field mice. Because soft furred rats are smaller than rats, I would say this puts them at a disadvantage of appearing as prey. I would definitely NOT try it. They do not communicate in the same way, and as I said, they aren’t just two breeds, but two species all together, so no reason in mixing them, same as with hamsters as you said. PLEASE do not just “try it”. These are living animals, not playthings. Listen to your research, or do more if you aren’t convinced. If you want to get some soft furred rats, keep them separately. Plain and simple.