I just got permission to trap a large river that has LOTS of muskrat houses. One area in particular has 6-8 houses that were built this year, not broken down at all. The problem is, there is no vegetation around. All of the cattails have been chewed off. No feed beds, no bubble trails in the ice around the houses, and only one toilet.

My question is, would these muskrats have built the houses, and abandoned them the same year? I don't know if I have ever heard of them doing this. Any ideas?

Yes they will do that.
If there is no food available, they will move. They won't starve starve themselves just because they built houses there.

The cattail roots Is what they eat In the winter. So they may not be gone.

If there was enough vegetation to build that many major houses there should be roots under the water for food. They may be feeding on or in the houses instead of feed beds. You said bubble trails, can you walk on the ice? If you have that much ice soon there should be some pushups if not then the rats may have moved on.

Bryce

Rats will move if they perceive it's getting to shallow even though there seems to be enough water. Have seen it many times, houses built and abandoned all in month.

I have also noticed that many times rats will build huts aggressively during the first skim ice but will still use dens until the ice gets thick. The time to trap houses is during that rush to build time. After that setting houses for me has been a low percentage set.

Bryce