It turns out that “I’m a lion, hear me roar!” should probably be changed to “I’m a lion, hear me snore!” The king of the jungle racks up enough sleep to make the average house cat look extremely active by comparison. Male lions spend 18 to 20 hours a day snoozing, while females get 15 to 18 hours of shuteye. The lionesses spend more time hunting and taking care of cubs, which is why they get slightly less sleep. And following a large meal, lions may even sleep up to 24 hours. Some lions sleep less, like the lions in Addo National Park in South Africa that sleep about 14 hours a day. This may be because they don’t have established social groups, so they need to spend more time protecting themselves from other lions and elephants that could trample them. Lions tend to be nocturnal, doing most of their hunting after dusk when it’s cooler, so most of their sleep is accumulated during the day. To escape the hot sun, lions tend to find sleeping spots under the shade of bushes.
Info source: https://www.sleep.org/articles/sleep-habits-of-lions/