Dimensions
203 x 229 x 3mm
The average human sleeps a total of twenty-four years over a lifetime.That's a lot of naps! Yet people aren't the only ones who enjoy a good rest; if you look around, you'll find that all animals have a biological need for sleep.But some animals snooze in ways that we would find startling-if not absolutely impossible.A sooty tern, an island bird, takes a nap in midair as it slowly flaps its wings.A fruit bat gets forty winks while hanging upside down from a tree branch.A bottlenose dolphin can put half of its brain to sleep while it continues to swim.What other remarkable methods of sleep exist?
