We're seeing a lot more of the babies now that they're 12 - they're big enough that we can see them crawling around inside the nest box, and every now and then a cute little nose pokes out from the entrance to the nest.
A baby mouse nose poking out from the nest tin.
Some of the babies have even gotten daring and left the nest: Ace, Deuce, and Runt have all explored the cage a bit. Each baby has primarily explored around the sides of the nest tin, trying to pry their way behind it (which they can't), though they've also wobbled a few inches toward the other side of the cage before turning around and retreating to the side of the nest box.
We've also chosen a name for mom-mouse: Rem. The name comes from the anime series Trigun (and thus is pronounced with the Japanese r/l consonant sound); Rem is a dark-haired, motherly figure who cares for the young Vash and Knives in the show.
Rem looking down at Runt, who is beside the nest tin.
The picture above makes Rem look a lot more caring than she often is when the babies are exploring: most of the time she's just off in the other half of the cage ignoring them.
As always there're more pictures on my Flickr page. I also shot a few short videos of Runt exploring and cleaning itself today (I used the video setting of my digital camera), though since each video is rather large, and I don't have good video editing software, I'm not sure if I'll post them.