i once bought two 'girl' mice, and a few weeks later had many more little ones it was very awesome, the mother did all that was needed to be done, and i just kept her healthy, it was awesome when they were still really, really tiny, but furry and their eyes were still closed

however, in relation to this topic , 4 of them (the girls, i had to separate genders) got killed by a snake (but it only ate one of them...the fattest one) and it was stuck in the cage cos it was too fat to get out i wanted to keep it as a pet, but dad took it to the edge of town and released it