You got THAT right! We must have hundreds of $$ worth of crinkly tunnels, whirligigs, balls with feathers, balls with dingle bells, soft balls, hard plastic balls, big stuffed mice, small stuffed mice, squeaky mice, catnip furry rats, you name it, and after a few minutes it's ho hum, what else you got?! But ANY new box, or large paper bag, by simply throwing it on the floor, can occupy them for days. They invent all kinds of games and uses for them. How we DO indulge our babies.
Large take-out bags, like from Outback, that have handles to them, we discovered we have to cuts the handles or else they get them around their necks and race off with the bag following. It gets pretty funny but we don't want them to attempt that when we aren't around to free them. Our Stella had the habit of sticking her head in a square kleenex box and then racing around bumping into the walls she can't see! Sometimes they pay for themselves in entertainment value alone. ;o)
The only other toy that they always play with is a round deal about a foot and a half in diameter with a circular grove around the edge where a heavy duty ping pong ball can go round and round.
They can't get the ball out of the grove and loose it.
Only bad thing is in the middle of the night you'll hear rattle, rattle, rattle, rattle.
Either me or my wife will have to get up and turn it upside down till the morning.