Cats spend 2/3 of their life sleeping, which equals to 16 to 20 hours each day! That’s more sleep than any other mammal except for opossums and certain types of bats.
Why does your cat sleep so much? Because it’s a predator with few natural enemies, so it can afford to take longer snoozes. And, being a predator, cats need sleep for the bursts of energy they exert while stalking, pouncing and wrestling with their prey.
Cats are able to sleep sitting up. Their muscles stiffen to keep them upright – in this position they are ready to spring into action at the first sign of prey (or trouble). Their sense also record scents and sounds during up to 70 percent of sleep, so they can wake up the instant they smell the scent of a mouse or hear the whistle of a bird.
See the original post and more pics of cats sleeping in weird positions and places at BuzzFeed.com.