Anyone with a cat knows that cats sleep 25 hours a day. Then when they wake up, they’re so exhausted they need another nap to recover from their sleep. Surprisingly, there is no definite reason why cats sleep so much.
The easy answer is that cats sleep so much because they’re lazy. The more likely reason cats sleep so much is because they’re lazy, but also because they’re predators and need to conserve their energy for the hunt. Whatever the real reason, it doesn’t hide the fact that cats sleep more often than practically any other animal.