Capes really are not practical for active kittens, but they don’t mind them enough to be upset. Green Arrow was carrying a corner of hers for a while. Capes handicap them in ways similar to claw trimming: what used to work, doesn’t but there’s always something else to do. A belly strap might keep the cape on the back, but they’d be sure to get entangled in each others’ straps. So, capes are a temporary entertainment.