We bought them a cage with an exercise wheel. They hid behind it. The exercise wheel is now in the hamper.
We bought them an exercise ball. They won't let us stuff them into it. The exercise ball is sitting next to the hamper.
We bought them little rat harnesses with bells on them. As soon as we get them on, the rats stuff their front feet into the neck hole and flop around all gimpy until they get it off. The rat harnesses are hanging from the bookcase.
On the other hand, Cat just tied one of them into a shoelace -- a goddamn shoelace! -- and not only did he not try to chew through it, he squirmed in protest when she tried to take it off. He wanted it back! And had to be manually reinserted into the cage, when normally both of them will just run down your arm to go home as soon as you open the door. HE WAS SMELLING THAT FLOOR OKAY?
It's just like buying toys for cats. You just know the instant you get their deluxe $79.99 kitty condo tower home, they'll ignore the hell out of it and play in the cardboard box instead.