When trapping in open water, never camp or make a fire near the pond where the beavers are located. In winter, after the ice has formed, it does not matter.
If you find a beaver house in winter when the snow is deep, and wish to know if it is inhabited, examine the house, and if the snow is melted on the top, you may be sure there are beavers in it.
Another way to tell whether a house is inhabited, is to cut a hole through the ice and shove down a piece of green poplar, filling the hole with snow. Examine it in about a week, and if the poplar has been cut, you may be sure you have found beavers.
The track of the beaver is seldom seen as they do not move about much in winter and on their trails their tracks are obliterated by the food which they drag into the water. The trapper does not look for tracks, but for more conspicuous signs, such as houses and dams with fresh cut wood.