A full house

Baby beavers spend the first month of their lives nursing inside the lodge. They start nibbling on branches when they're two or three weeks old.

Follow the link (or look up at the big monitor if you're reading this from the Science Museum of Minnesota's Mississippi River Gallery) to get a sneak peek inside the beaver lodge at the Minnesota Zoo.

If you look closely, you might see three new babies—or kits—born June 13, 2010. The other beavers are yearlings, born last July, and their mother. (Dad died over the winter.) Usually, both parents and the older siblings help take care of the kits.

In Minnesota, beavers breed between November and March, with one litter of three or four babies born in May or June. At birth, kits weigh in at less than a pound. But their eyes are open and they're covered in soft fur. And they're able to swim before they're a day old. Young beavers stay with their families until they're about two years old.