Will a weasel hesitate to enter a box if the trap is plugged up with s mouse?
I've seen tracks avoid entering the box.

No, just the opposite. The mouse will act like additional bait.

This here, I bait my weasels wth beaver or muskrat. If I catch a mouse that just gets added to the bait if there is anything left. Usually the weasels clean them out.

yes what they say , I see it as a good thing when mice are eating my bait