Kittens adore boxes. They are one of the most popular cat toys that don't cost any money. Cats love to get in and out a cardboard box, chew up its edges, and even scratch it to exercise their nails. Cardboard boxes can be used in various ways imaginable by cats. Maru has a huge fetish with cardboard boxes where he would do anything to try to fit his body into one.
Check out the video below to see two rascals flighting over a box. Enjoy!