People lie down, close their eyes and sleep for hours in one stretch, but the animal world has plenty of other methods. Some creatures rest half a brain at a time, and others nap on the wing or wrap themselves in kelp. Here are ten animals that sleep in ways humans would find surprising.
1. Sea Otter: A floating nap in a kelp blanket
The Animal Diversity Web entry for the sea otter describes a marine mammal that spends nearly its whole life in the water along North Pacific coasts. That includes sleeping, which sea otters usually do while floating on their backs at the surface.
Resting otters are often seen in groups called rafts, and they are widely reported to wrap themselves in strands of kelp so they do not drift away on the current. Mothers may also float with a pup on the chest, rocking gently with the waves while both rest.