We recently bought a child's foldable play pen (For our dachhsund who injured her back, who is completely confined for a atleast a month while she heals) and as soon as I took it out of the box, and placed the box on the floor...the kitties claimed it as their own! I keep large boxes for cats, and i use small boxes for my rats and hamsters.
boxes are a favorite around here.. Tabbi will try to squeeze herself into any box that she thinks she will fit in.
When she was younger, I once found her in an empty 12-can pop carton. I showed it to my (now ex) hubby, and told him that cats are easy to please, and he insisted that I put her in there.
James had bought a new desk chair over the summer.. the cats claimed the box as soon as it was empty.. we let it sit out for them to play with for about 6 months or so, they had eventually clawed it up enough that it wasnt much of a box anymore.
My aya gets all excited when I'm opening a delivery from Amazon.jp now. I'm not sure if its the sound of ripping plastic and paper, or that she knows she gets a new box to chew on and push around for a couple days.
The 30 pack beer boxes are the best, particularly when you put them in a long hallway with a tile floor. They run down the hall, leap into them, and sled down the hallway.
Oh yeah, Whisky loves boxes! I'll put one on the bed and he'll climb into and go to sleep. Instead of the nice soft bed he was JUST sleeping on! At his age(15), he doesn't play much anymore.
Mine always remind me that no mater how much I spend on cat toys, boxes are still their preference. Mine also go crazy for that strip of plastic that you peel off the milk.