Up to 21 days
As long as there is one male mouse and one female mouse in the same cage there will most likely be babies.
About 21 days.
No way. If the baby mice are in the cage long enough with the mother mouse, the mother mouse will indefinitely eat the babies.
2o days
Rats might abandon their babies if they can't take care of them or if they are too stressed. My rat had babies and it kept abandoning one of them. We tried to feed it, but then decided to take it to the pet store. They put it with a mother mouse and it started licking it. A few days later we visited the pet store again and they said it died. If your rat abandons its babies, feed them with soy milk.
It is normal for a mouse to have 10-12 babies. My mouse had 10. The most babies a mouse has reportedly had is 17.
no they will fight, and some babies may die.
let the mother take care of her babies you just have to take care of the mother like feeding her making sure that she has plenty of water to drink and a clean environment.
babies
You might be able to foster the babies with another nursing mouse, or even a female mouse who isn't nursing--mice are able to lactate when needed, but it might take awhile for that to kick in. You might have to foster the babies yourself. This site will tell you more: http://www.thefunmouse.com/info/orphanedmice.cfm.
TAKE IT TO A VET!!!!!
No! Any male mouse or rat will eat any mouse babies. dont let male mice with babies until they can see and have fur!