Yes sweety your right about the stuff they put under the skin, its sorta like an implant......but she did not do that to the mice.....she fed them a type of supplement to see if they would grow larger than the mice fed on a regular diet, maybe i should get the name of the supplement from her....But yeah, it was not injected, it was fed to them.

She said they are good breeders, maybe i could give them to one of my friends breeding stock and trade her for some rats.

Should i maybe drill a small hole or two in the lid ?