Your mouse has necrosis. This is either from the mouse biting its tail, or more probable, someone pinched its tail. Sometimes it kills the mouse, other times it drops off and the mouse will be fine.
Purple mouse
Our mouse had a purple tail (just on the end, about 1-2") turning black and falling off, due to a fight with another mouse that damaged the tail and caused lack of blood supply. The vet gave both oral and topical antibiotics. He also told us that IF it spread to the base of tail, that was the spinal cord and mouse would need to be euthanized. (If that happens, the mouse would die in a lot of pain and it can't be fixed.) We had a happy ending: the damaged end of the tail fell off, everything else healed, and the mouse continues to live a happy and active life......in a separate cage! You need to get YOUR mouse to a vet for some antibiotics!
It is purple
no sick mice should be caged with healthy mice, unless you have the mice checked by a certified vet. Also if the sickness contagious to other animals you should go to the vet and take the sickness taken care of. So if you have a sick mouse DON'T house it with other mice.
Your choice
black
100 *I.G.G.Y. (fuzz ball that bites your mouse) Purple daisy, purple daisy, black moon Ignore that guy ^ its; This one is very tricky, because snookums needs any 3 star blossoms, so you must perfect one flower at a time, i would say to get one correct, then do another one and hopefully your third one will be the right colour. Oddie (doughnut) Yellow star, black star, Purple star
A black widow surely can kill a mouse , I have seen it with my own eye's .
it depends! if the mouse had rabies or a bad sickness then the guinea pig coud POSSIBLE die. but not very likely.
Black .
Yes, there are black mice.
Yes!