Pet Forum / Mammals / Rats / September 2007

I've got a girl named Io. We initially paired her with a male,
Splinter, but there seemed to be no interaction between the two, so we
removed Splinter and matched her with Dimitri. She gave birth about
three weeks ago to only 4 babies, one of whom died.

The survivors (Scope, Iris, and Prophet) are all healthy little guys
with dumbo ears and long fuzzy coats. Today, though, when moving the
cage, I made a discovery: Io gave birth again! There are 5 new babies
in her cage.

Is it possible for births to span this great a range? I can't see how;
it was my understanding that gestation took about three weeks and Io's
had no contact with a male (beyond her newborns) for more than length
of time. And, of course, she was pregnant until three weeks ago.

Is it possible for these most recent babies to have developed so
slowly they were born of the same father but weeks later? Can a rat
have long-gestation periods and/or carry the children of multiple
fathers at once?