My vet at The Feline Hospital in Salem MA told me several years ago to put all wool toys away! they were popular a while back. cats swallow them and yes, I suppose, are unable to digest them. I felt saddish because they love the real wool so much! But they do swallow pieces for sure! Wierd but true! (Wonder why cats never became sheep herders like dogs?). Anyway- I'm sure you're vet or any website you go to will tell you the same- all wool toys now are synthetic- cats are not excited by them and not inclined to eat them!