When will baby mice be mobile?

Question
How long before baby mice start exploring?

We went out and bought two pet mice 16 days ago.  We thought they were both females---is it possible to have babies in sixteen days?  Well, one of them had eleven babies tonight.  Pretty exciting!  What I really need to know is---they're in a critter trail cage right now, with the plastic tub on the bottom, wiring around the middle section and then plastic on the top again.  I'm assuming the mice will be able to get through the wires eventually.  How long will it take them before they start exploring/trying to escape?

Answer
Dear Tracy,

Mouse gestation is 21 days. That means hopefully you do have two females and, (at least) one, was already pregnant (cross your fingers you don't find litter #2 in a day). Examine their rear ends to make sure. Do they look the same? A boy  mouse has very large testicles which looks like a big butt. You're going to need this link to sex the babies anyway:

http://www.thefunmouse.com/info/sexing.cfm

If you do have a male and a female, get the male out asap!! They can mate pretty much immediately after she gives birth.

They need a solid cage before their eyes open (around day 14), so at age 12 days. They may not really climb much for another couple of days, but better safe than sorry. It's not that they will try to escape before they are weaned, but they will explore and get lost.

There is a ton in my archives about babies and mouse raising. Please write back if you have another question. Have fun with the babies!

squeaks n giggles,

Natasha
<:3   )--~