I like the idea of making a ramp to encourage the use of their back claws. We may have to make it a little lower for our cats, but it still seems like a great way to encourage exercise. I could attach it to a bookcase
These cat window shelves are Ikea hacks, just regular shelves with a nice soft bed on top. Would be a good idea to put Velcro between the bed and the shelf to help keep it in place. And never mind the link, it doesn't lead anywhere of relevance.