My son had pet rats which did the same thing during the night. (Their wedding quilt was just a little too close to the cage.) I was able to find scraps that were the same fabric and on the top I just appliqued the same piecing over the top. I did the same on the back. If I were to try to find the spot from the top I couldn't do it. The back was a print whole piece so it was much harder to hide but they don't look at the back so it worked great!