Hard to say Judy. It may be hormonal as she began to show real aggression during the breeding cycle for this litter and has just gotten progressively worse. From what a few other rat breeders have said though, she's likely to never be trustworthy again with her litters or even other rats let alone around us or the kids. Apparently once they go mean like this they rarely go back to a more normal rat personality and I hate to see healthy rat pups destroyed like that by their own dam.

She actually didn't start destroying her young until we figured out how to block her from biting us. It's like she's taking out this unnatural instinct to hurt us on her own litter. Just very odd behaviour. Glad I don't see this in my colony normally and I certainly won't use any of her young as future breeders just in case.