10 facts you didn't know about beavers

Extinct in the UK for 400 years, the Great British beaver had been merely a conservationist’s dream until they were re-introduced to Scotland in 2009. And a year later the first of the buck-toothed mammals to be born in the wild since their re-introduction were spotted in Argyll, Scotland.

Here are 10 facts you might not know about our furry companions:

1. They have a third transparent eyelidthat helps them see underwater.
2. When they fell a tree they waste nothing, systematically eating the bark and buds before cutting up branches and sections of the trunk to carry for use in dams or lodges.
3. They can remain underwater without breathing for up to 15 minutes and swim up to 5 mph.
4. If a beaver is hissing it’s best to steer clear, it may be frightened.
5. Although beavers are social animals, they are lone engineers and work independently with little contact with each other.
6. As with all rodents, a beaver’s front teeth never stop growing.
7. In the USA, beaver damage costs around $100 million in property costs every year.
8. Luckily dam-building can prevent floods as well as cause them: the wetlands that dams maintain soak up floodwaters, prevent erosion and create an ecosystem that breaks down pesticides.
9. A beaver's tail is a little like a Swiss Army knife: it is used as a rudder, a third leg while standing upright, as a lever to drag branches and can be slapped on the water to warn other beavers of danger.
10. Folklore holds that beaver tail was a delicacy among mountain hunters in Canada. US President Barack Obama ate one on a recent trip to Ottawa, though his was made of wholewheat dough.