Why do beavers build dams Thanks

PLEASE READ THIS! i found this on a website. this answers your questions!

Beavers are busy.

This fact has been scientifically proven - and for most people this explains why beavers build dams. What else would a giant hyperactive stream dwelling aquatic rodent do to release all that busy- ness? But does this explain the beaver's odd behavior? Only beavers build dams.

Humans have always marveled at the beaver's ingenuity since he always picks the narrowest part of the stream for the site of his dam. This fact was always cited as proof of the beaver's intelligence and engineering skill. Yet even a modest acquaintance with beavers will soon reveal that they are far from cunning beasts. It was at this stage of the debate that a young grad student entered the scene and began to investigate.

He noted that beavers living in ponds and lakes and along rivers never build dams - so this compulsive beaver barrier building business was not a result of their busy nature since non-dam building beavers found an outlet for their busy-ness in some way other than dam building. He therefore obtained several pairs of beavers (all with proven dam building track records), released them in different environments and then sat back and watched what they did.

Those released in ponds and large rivers burrowed into the bank, set up beaver housekeeping and then showed no more desire to construct anything beyond their holes. Those released along streams, however, found likely looking pools and then proceeded to deepen them by constructing dams at the narrow, shallow, downstream end. This set the investigator to thinking...