No. The gerbil will eat the mouse
You can put a new mouse in the same cage as another, but if your mouse prefers living alone, don't put the mouse in the cage. The older mouse should be better off solitary.
If they're spayed / neutered, yes.
You must be talking about A rodent, I.E. Rabbit, Rat, Mouse? Seperate them.
if you don't buy the male mice at the same time while their in the same cage they would fight bitterly but 2 females might not have a problem with each other but the safest way to get 2 mice at a time is from the same cage.
no
no they will fight, and some babies may die.
Same place as a male rabbit
NO
As long as there is one male mouse and one female mouse in the same cage there will most likely be babies.
Get a female mouse and male mouse, keep them in the same cage, they are likely to mate or breed if they're alone together.
Probably not. But I read a book in my school library about gerbils and the author of it said that one of his friends put a gerbil and a mouse together in a cage and they worked out OK.