My kittens have all kinds of toys, some of which I spent much more money on, but these are by far their favourite. I have hardwood/tile floors through the house, so the springs roll/bounce/skitter satisfyingly. They are a perfect size and shape for the kittens to pick them up in their mouths or their claws to throw them around, so they can play by themselves easily. They do get lost in small spaces easily - every day I am retrieving them from under the fridge, the TV cabinet, the computer desk... I thought they would need frequent checks for chew damage, but I'm finding they stand up to kitten chewing much better than I would have expected. In conclusion, I am ordering a second packet of these!