Pros: can be heard due to small bell inside ball
Cons: cat claws may get stuck in balls, plastic may break or chip causing little plastic hazard pieces/jagged edges, and bell may then fall out.
Got these as a gift, and thought they would be excellent for throwing around, since my cats often like to chase Ping Pong balls, but these were very disappointing. Don't know if it is just my 2 cats, but they would get their claws stuck in the balls, while trying to bat at them, or throw them in air. Younger cat bit down on one ball, and plastic cracked, causing little bell inside of it to fall out, and making the edges all jagged and brittle with small plastic pieces left on the floor. Not to mention, that the bell is very small, and I worried that the cat could swallow it, once the ball broke. Even with close supervision, I would not trust these balls.