What is their diet like? Also Does Millie sleep against the side of the cage walls or objects? That can cause bending but breaking is a little odd. Could her cagemate be chewing them off? That sometimes happens when they groom each other.
Chinchillas are naturally skittish and need to be socialized in a careful manner to overcome that. Taming a chinchilla is a process that can take several months and should be done with great gentleness and patience.
How old are they? Did you get them from a breeder or do they have a previous owner?
Is this a male and female pair? These sound like male and female names.
If it is you will become a breeder whether you like it or not as chinchillas are sexually capable at 3 months and breed indiscriminately.
It is dangerous to breed before 12 months because females are not always able to safely bear offspring until they are fully grown.
How long have they been paired together? Separating a breeding pair can be dangerous and cause severe depression in one or both animals. If they are a pair, you don't intend to breed, and you wish to separate them, you will have to take special precautions.
