Better catch them before freeze up if you don't, they will all be dead. Or they will have moved on to better locations.
More than likely moved on.
Always have been a lifelong learner and never thought I knew just about everything about anything. The older I get the less I seem to know. Case in point.
Years ago a commercial fisherman by the name of Jeff Morrison contacted me about becoming a trapper ed instructor. Said he was at that point in his life where he wanted to share his knowledge with younger folk and encourage them to get and stay in trapping. He had to jump through a couple of hoops to become an instructor including helping out at a live trapper ed class. When it got to that point I invited Jeff down to our class to help us educate a couple dozen students. He asked what he should bring. I said bring your knowledge and whatever you need to deliver that. We were camped there at the clubhouse and he asked if he could bring something to share for dinner. I said sure.
He showed up with some trapping gear, a turtle trap, and three live snapping turtles. At the end of the session Saturday he butchered the three turtles with a crowd of wide-eyed youngsters circled around him. Cleaned up the meats, dropped them into a kettle along with other goodies, and set that on the grill over the campfire. Awhile later we were dining on turtle stew.
Around the campfire that evening the talk got around to muskrat trapping on the big river. The refuge. I asked him if he was out there opening day. Nope . . he waits until the ice is thick enough to hold his ATV. I shared my vast knowledge about the 'rats all hammered by multiple trappers by that time. He said it's worth the wait. I said educate me
Jeff made his living off the river. Commercial fisherman, trapper and part-time carpenter. He knew the river well. He said, under normal conditions, there are two major migrations of muskrats on the big river. The first is occurring now. 'Rats that detect cold weather coming combined by dropping river levels leave the bank dens and head out to build huts. The second migration comes later once ice forms on the back sloughs and marshes. As ice thickens these 'rats that are in shallow waters continue to migrate out to deeper huts. Many of these huts have been trapped out and are vacant. By the time Jeff got out there with his ATV towing his sled with willows and #1 jump traps the competition was home on the couch. He had the area to himself. As the ice continued to thicken the migration slowed, but was still there.
My last visit with Jeff was prior to his passing in 2011. Heart complications. He knew it was coming and had videos made of himself talking to his grandkids. If you visit the Upper Mississippi Wildlife Refuge Center on Brice Prairie, you'll find a small section featuring Jeff's work on the river and if memory serves correctly you can push a button and hear Jeff talk about his days on the river. Fellas like that are gold.