From the pictures it a little difficult to tell how wide those trails are. If it was made by something in the feline family, it would have to have been a mountain lion. On a side note, there was a mountain lion spotted here in Chicago a few years ago and ironically that topic came up during the inspection, but not because of the trails in the insulation. The big cat was spotted in the alley were my clients are currently living, about 15 miles away from the inspection. I think Bill is right and it happened during a re-sheathing of the roof. The curvy pathways go all over the attic, twisting and turning from corner to corner. No foot, hoof or paw prints in the insulation between the joist or below the top of the joists. A small amount of tear-off debris sprinkled on top as well. Really it should have been more obvious to me when I was up there. I was a bit uneasy thinking that a big animal was gonna jump out from the insulation at anytime.[:-bigeyes