One of my kittens used to sleep inside a bread basket. I had it on a shelf, and I found him sleeping in it all the time, until he became too fat to fit inside. Of course I had to make a new basket for bread.
I had 3 and 4 cats at once. My husband and I noticed that most of the time they would practice triangulation, much like a pride of lions do. Those of you who have 3 or more cats--notice how they position themselves when they are together. Do they form a triangle? Supposedly this type of body positioning is used when hunting and to protect the pride from predators. Cats are the most interesting creatures.