in small rivulets of insufficient depth, these clever little
creatures dam up the waters until they are deep enough.
The banks thrown up by them across rivulets for this
purpose are of great strength, and would do credit to
human engineers. Their lodges are built of sticks,
mud, and stones, which form a compact mass; this
freezes solid in winter, and defies the assaults of that
housebreaker, the wolverine, an animal which is the
beaver's implacable foe. From this lodge, which is
capable often of holding four old and six or eight young