QUOTE : Yet beavers are as balletic in water as they are clumsy out of it. They can hold their breath for up to fifteen minutes, and their underwater gymnastics are powered by webbed hind feet. Transparent eyelids allow them to see below the surface, while a second set of fur-lined lips close behind their teeth, permitting them to chew and drag wood without drowning. Building dams expands the extent of beavers’ watery domains, submerges lodge entrances to repel predators, and gives them a place to stash their food caches. Ponds also serve to irrigate water-loving trees like willow, allowing beavers to operate as rotational farmers: They’ll chew down vegetation in one corner of their compound while cultivating their next crop in another.