An Eager Beaver is to describe anyone who is exceptionally keen and industrious or who volunteers to undertake all manners of jobs and then puts everything they have got into them.
Beavers are among the most intelligent and hardworking of animals as well as being remarkable ‘engineers’, able to build dams, houses, canals and cut down trees. Besides rearing their own three or four at a time, they also take over the raising of orphaned beavers. The word ‘eager’ is derived through the French aigre from the Latin acer , meaning sharp, keen.
P.S: mud, stones and wood, let’s build!