Back in the 70s I had the same problem and I painted mine with creosote, but I don't eve know if that is available any more with all the EPA restrictions in place nowadays. If you have that box trap, I'd use that first and bait it with some salt to see if they will go in after it. I just built a new blind in upper MI with OSB and will be going up in a week or two to cover the whole thing with some scrap steel I got from a pole bulding project down here where I live. It's white, so I'll have to get some spray paint to camo it, but that blind will last forever with no weather or porky damage.