will a fisher go into a mink box? if so are there any sets i can use to avoid fisher?

Make an entrance hole in the box too small for fisher to get his head in.

2 1/2 inch hole

and then if they still want the bait they will chew the hole larger.

thanks i had a feeling they would do that.

To be honest with you the restrictive entrance hole WILL keep most fisher out of your boxes.

2 1/2 inch hole is a bit big,a fox can get its head in a 2 1/4 inch hole and their skull is a bit wider than fisher.
1 1/2 inch hole would be better for mink.

You must have pretty small mink. That's basically the size hole we use for weasel boxes here out west.

That was my thought too. I use a 1 3/8 inch hole on weasel boxes. I've never had a mink get into one. You will however have coon stick their hand in the hole and get caught. I've never caught a fisher this way, but I would assume that they could easily get caught the same way as a coon.

Wire the trap, not the box. If something big gets caught by the paw, they will chew out the opening and will no longer have their arm through the hole.

If you want to know how small a hole an animal of the weasel family can get through,measure the widest part of the skull.You will be surprised how small a hole they can get through.
An adult mink skull is 1.2 inches wide.

than you everybody for the responses i will work on adjusting my boxes to have a hole

Yes their fleshed skull is small but lets be realistic, they still must get their shoulders through the hole, and we really don't want to make it to difficult for them to get caught.