The beaver talk reminded me of some lines from May Sarton's Journal of a Solitude:
"It is a catastrophe to have five baby woodchucks under the barn, though they are adorable, like small toy bears. Of course, they have eaten down the hollyhocks."
and then the next entry...
"I am leading a cluttered life these days. The baby woodchucks are devouring the garden, but they are so happy- how can I kill them?"

I know your beavers weren't real, but it reminds me of how funny it is when animals drop into our lives- it is not exactly out of the realm of possibility that a family of beavers might come live in your yard. I once found my dog barking at a crayfish in my backyard in Virginia- it was after a heavy rain, so he must have made his way over from the stream a couple houses over. The crayfish was baring its claws, obviously saying, "F you dog, shut the H up- do you see these pinchers?" I'm not sure if crayfish have faces, but when I recall that incident, I see that crayfish with a pissed-off look on its face.

And, in the woods behind my neighborhood where I grew up, there was a pond with a beaver dam. We could spy on them from far away. Their dam/house was SO freaking cool. There were pointy tree stumps around the pond that had (duh) been gnawed down. One day the older neighborhood boys destroyed the dam. If that isn't evil, I don't what is... to destroy all that hard work?