I have set on lodges at times,when set opportunities were limited.I also do not hesitate to set near a bank den.But I just never set the entrances.
Remember 95% of all my beaver are taken with castor mound sets,and I use 330's only. I want the entire colony to exit and enter their lodges freely--plug an entrance with a dead beaver and you greatly decrease the chance of this happening.
I usually go off to both sides of an entrance and put in several sets.Here again,I want to take as many beaver from a lodge or den the first night. Bang them quick , and you experience a lot less problems.
A 330'd beaver is never going to get square shy-- when he is already in the fur shed.
Most times, I never even bother looking for lodges or dens. If I find where they are going up to cut, or find some peeled sticks , I am already where I want to be. In the spring,I don't even worry about setting on sign,at ice out time sign can be very minimal or even non-existant.
But again-- thats my style of trapping. It has provided me with a means that works for me, and works well. With the limited time I have to trap open water beaver, I need to hit them hard and fast.
May you all enjoy trapping the kings and queens of the water ways--BEAVER, you got to love them.( I sure do.)
Tom