Bedrooms Are Multi-Purpose Rooms. In Afghanistan, not only do family members all sleep in the same room, but in the morning, they fold up their mattresses and blankets so the room is available for daytime use. Even houseguests are typically expected to sleep in the communal room.

Sleeping on the Job. Two-thirds of Japanese people get less than seven hours of sleep after a hard day at work, which is why many Japanese workers engage in the cultural tradition of inemuri, or napping on the job. Historically, it's meant to show how exhausted a person is from working so hard.

Netted Beds. In areas where malaria is a threat (such as sub-Saharan African countries, like Ethiopia, Mali, Rwanda, Senegal, Tanzania, and Uganda) beds are often surrounded by nets. Malaria is a serious disease that's usually transmitted when an infected mosquito bites a person—and it's a lot harder to fight off mosquitoes while you sleep, since you generally can't feel them biting you. So mosquito nets, which are often made of strong polyester, multi-filament fibers, attempt to reduce transmission of the disease by keeping mosquitoes at bay.

Brits Drink Tea and Sleep Naked. Tea isn't just for breakfast! Forty-three percent of people in the United Kingdom have a relaxing drink, like tea, before heading to bed. And a third of them ditch their PJs to sleep in the nude!

The Siesta. In Spain and many other Hispanic nations, the siesta is part of the culture, as businesses often close for several hours to accommodate the mid-day rest. While the siesta can span a couple of hours, only a fraction of the time is actually spent napping; first, there's lunch with family and friends, then a rest. Because of the siesta, people often work later into the evening.