I had mice do the same to my husbands stand a few years ago. I went to the upholstery shop and got a new piece of foam( got a piece thicker than the thin piece it had before because the seat never was really comfortable before, to thin of foam) and then took the old camo pants he didnt wear anymore and cut them open . The pants at the thigh were just wide enough to cover the seat with no sewing needed, and used them to cover the foam. I then used a staple gun to attach the fabric to the bottom side of the seat and painted the bottom side of the seat including the staples with camo paint. Works great now and is very comfortable.Hope this will help you.