I have 15 snakes and 2 rats. The only thing I do is wash my arms before I change waters or clean cages. And I handle my boas usually after a shower so I am sure to not smell like rat. They do seem to notice the smell but all of my balls could care less. I would say it increases your chance of getting tagged but it is definitely not as bad as I expected it would be when we got the rats. I really like all of my snakes but nothing compares to the companionship from a couple of lazy rats. My boys are passed out on my shoulder right now fighting for room on one side. They really are quite a rewarding pet to keep. I actually got interested in them from pictures posted by a user here.