Sperm whales are the biggest animals with teeth! They live deep in the ocean. But they need air to breathe. So how do they sleep? Scientists wanted to find out!
Researchers put tiny tags on 42 whales. The whales were near Norway. The tags recorded sounds and movement. The whales sleep standing up in the water! They rest for about 10 to 20 minutes.
The scientists made a cool discovery! The whales blow bubbles while they rest. The bubbles help them stay under the water. Without bubbles, they would float up too fast. These giant animals are really clever!
