Anyone got some ideas on what kinda bait I should be using?
When I trapped muskrats as a kid we did not use bait. look for tracks and a path where they have been entering and leaving the water. Set your trap
under about 4" of water with the chain anchored offshore. (tied to a brick) When he enters or leaves the water and steps in the trap, he will panic, head for deeper water and drown.
I sold enough muskrat pelts in the early sixty's to buy my first new .22 rifle. They were bringing $8 each.