How Do Different Animals Sleep?
Big Sleepers
Predators, such as lions and wolves, tend to sleep more than their prey. They also spend more time dreaming, although scientists don’t know why.
Light Sleepers
Giraffes don’t get very much sleep — only a few hours a day. For giraffes, sleeping is awkward and leaves them weak to their enemies. So giraffes mostly take short naps while standing up. But they do need to lie down for half an hour or so of deep, dreaming sleep. It can take a whole minute for a giraffe to get back up on its long legs again.
A Comfortable Bed
Most animals like to find a safe, comfortable place to sleep. Gorillas make themselves sleeping nests of branches and leaves on the ground or in a tree. Every gorilla makes a fresh new nest every night, even if they haven5t moved far from the one they used the night before.
Half-asleep
Dolphins are air-breathing mammals that swim in the sea. But how do they sleep? If they stop swimming to take a nap, won’t they sink and drown? Scientists studying seals and dolphins have discovered a surprising answer — these animals can sleep with one half of their brain while the other half stays awake! While the right half of the dolphin’s brain is asleep, the left half stays awake. This lets the dolphin keep its nose above the water so it can breathe. After about 20 minutes, the sides switch, allowing the other half of the dolphin’s brain to sleep.
Do Bugs Sleep?
Bugs don’t sleep in the same way we do. But they do have periods of rest every day. Dragonflies often have a favorite spot that they return to time after time to rest.
【小题1】What can we know about giraffes’ sleeping habit?| A．They are big sleepers. | B．They don’t need deep sleep at all. |
| C．They usually stand up while sleeping. | D．They tend to sleep more than their prey. |
| A．Wolves. | B．Dolphins. | C．Gorillas. | D．Giraffes. |
| A．They sleep while flying. | B．They sleep on the surface of the water. |
| C．They sleep in the same way humans do. | D．They return to the same place to take a rest. |
