I don't trap a lot of beaver, but to paraphrase Paul, I trap all I have. Many times a new beaver trapper causes so much commontion setting up, that the beaver are put down for long stretches at a time. A pinched beaver esp can be very wary. In a new house, that is untrapped, etc- I find it hard to believe there is only one beaver in the pond.
Something I do in situations where I think there are beaver, but there is no action, is to pull the traps and vacate the area for a week or so. No human activity over that period of time should get the beaver active. Before you pull out- study the area so that you wil be able to recognize new activity.
And I don't care what tim says.....