Voices

Since some days, I don’t know exactly from when because I didn’t pay much attention to it – I hear new voices.
I thought it was a bird singing. But recently I have learnt that beavers also make such birdlike noises. They whistle. So this sound which I am hearing maybe is just beaver’s whistling? I could see many beaver’s traces in the grass. It looks like my beavers are very active and are able to come very near my settlement. 
Right now I am also hearing a whistling... Very close to the house... It looks like they are everywhere...
I feel a little bit like surrounded by zombies :) Beavers come up only at night. And it’s night. Very late night.
The biggest beaver can have even up to 140cm length. It would be scary to meet such one in my yard at night ;)