A few months ago, I was at a local PetSmart and bought a bag of three rubber balls (a blue, a green, and a pink) which became Arthur's favorite toys. These rubber balls are different from any others I've seen because they have these small rubber spines sticking out and they have bells inside which jingle as they roll.
These balls are superior to any others I've seen or bought because they roll slowly and are easy for cats to carry in their mouths.
I wish I had video of it, but Arthur will actually play fetch with the pink ball (his favorite color for some reason). If I throw the pink ball up on a chair or a couch, he'll grab it in his mouth and bring it back to me to throw again.
Unfortunately, these balls are starting to wear out and PetSmart doesn't have them anymore. I've been to dozens of pet stores and searched tirelessly online, but I haven't seen these balls anywhere. Does anyone know where I can find them?