We currently have two females housed together that were together with the same male before he moved on. One delivered babies shortly after he left making us believe she may have been pregnant when we got her. The other looks about ready to explode any day. The first one had 9 pups and so far all are still alive after 10 days. Now here is where it gets interesting, the first week the actual mom would not let the other one have anything to do with the babies. After that one day we look in and see the prego nursing all the babies while mom is lounging under the feeder, I guess she decided to take a break. Now it looks like they share the litter as they have built one nest and both sit in it and the babies just move from one to the next!

My question is since the other one has not given birth yet is this a problem?

How long before a rat gives birth does it start to produce milk?

Thanks!