This beaver was a newborn when her parents were killed, and she was taken into the care of a family of wildlife rehabilitators. As she's grown, she spends more and more time outside with other rescue beavers, but is still welcome in the house. Yet a beaver's just gotta beaver, and no matter where she is, the instincts will kick in. At Christmastime, there's a lot of extra objects around the house, what with all the decorations, wrapping, and gifts, so this young beaver saw the perfect opportunity for building a dam. Note the attention to detail, the swift judging of each piece, and the careful placement. I think she did a marvelous job! -via Metafilter