Kill them as fast as possible or try to definetely avoid beavers in your pond.
1) They destroy trees (as you saw);
2) They dig holes everywhere and not only one per beaver. All shoreline can be full of beaver holes. By the way, don't expect them to move dirt outside the water;
3) They bring tree branches into water for their construction works etc.
Bad landscape, bad water quality, bad swimming possibilities and sometimes even bad smell around. Do you need it?
