Mother mouse separating pups

Question
My pet mouse gave birth to 11 pups (5 of which have since died/been eaten) about 2 weeks ago.  The surviving pups have been doing fine, their fur has started to grow in, though their eyes are still closed.  However today we awoke to find that the mother mouse has separated the pups, she has moved 2 over to the other side of the cage (along with most of the bedding) the other 4 remain where they were originally...  Is this normal?
Thanks.

Answer
This is nothing to worry about, mothers move the babies if they feel the first nest is under threat or if the nest is wet etc. She may move them back or even to a third location. Try to keep her as stress free as possible which means placed the cage away from noises, drafts and predators (e.g dog or cat).

Please feel free to ask any more questions.