Bank beavers and lodge beavers together?

[blakdog]

Shawn and i have been trapping a beaver pond that we came across after the ice formed. There are 2 lodges some distance apart and both have fresh recent work done on them. The kicker is now that the ice is out. We came across a bank den with a defined run into it! Could there be 3 active colony's on this pond? I was under the impression that if they could dam it they would build a lodge, why would they build a bank den also? This pond has been here for ages.
Troy

[Bogmaster]

 Anything is possible when it comes to animals. Some beaver prefer to build a bank den.I have seen several bank dens--and they also build dams.
 It may also be a den built by the lodge dwellers.Or it may be an old bachelor.Lots of possibilities--only you can provide the answers. Keep track of age and sexes of all the beaver you catch. It should give you better insight into what is going on.
 Tom