When it comes to biting it really depends on the circumstances.

To protect their litters, it is ok and I will tolerate it.

Now if they don’t have litters and do bite when I do regular maintenance or check on them, I have a zero tolerance policy (whether it is with mice or rats), same thing with individual that are overly aggressive toward one another.

Note: I rarely have issues and when I had it has often be with either Albinos or Pet-store animals.

I do no longer holdback albinos whether it is mice or rats (I just have issue with them for some reasons).