Quote Originally Posted by cobweb2000 View Post
This is why I get upset when I see people keeping rats in tubs that are 7" high, a large adult can barely stand up in that tub much less strech up on thier back legs.
I haven't noticed a difference between males kept in a rack as a breeder, or rats allowed cage height their whole lives.

In my colony, it appears to be mostly genetics that determine the rats size, and fat is based on food intake with genetics.

However, they are perfectly capable of stretching their legs and back in a tub much like a cat does when they wake up. I see them do it everyday. :/