Last week driving on John Nolen over the bay, we saw a muskrat sitting on the ice next to the open water on Lake Monona. The next day, walking on that little drive from the Limnology Building to Mem Union, there was a muskrat sitting on the ice, in front of the open water on Lake Mendota near the sailboat storage area. He dove in when we walked past but was back when I returned.
The next evening at dusk, walking the dog along the Yahara from Jenifer to Lake Monona, I counted five muskrats swimming up and down the river. They were diving, then coming up a few feet away, then diving again. The dog never noticed them.
That was a lotta muskrats. I think they're going to swarm this year.