Hey Purrley,
I had a similar situation, thanks to Stump. I hadn't realized what he had been doing to the underside of the box spring on my bed until one night when I was in bed reading, I heard this scratching noise. When it didn't stop after I had yelled "No, Stump!" several times, I got out of the bed and looked underneath. There was Stump lying on his back, pulling himself by his front claws the full length of the bed! When he got to the end, he'd turn around and claw his way back to the other end. It was so funny I had to laugh, even though the material covering the box spring was pretty badly shredded. But hey, who's gonna know? (except Stump, me, and now everyone on Pet Talk! )