How Do Whales Sleep? And Other Whale Trivia
- Species conservation
- Natural history
You already know whales are majestic creatures, but how well do you know your whale facts? From how whales sleep to what their groups are called, take a deep dive into this trivia. Plus, see how you can be part of critical conservation efforts to protect these animals.
Ready to put your knowledge to the test? Click “Show More” to reveal the answer and more facts about whales.
How do whales sleep without drowning?
Whales sleep by “turning off” one half of their brain to rest while the other half remains alert.
This is because as air-breathing creatures that live in the ocean, whales have adapted to be voluntary breathers, which means they consciously control their blowholes. Because whales must maintain awareness to breathe, they “turn off” half of their brain to rest while the other half stays alert to prompt their next breath.
In this state of half-consciousness, some whales will swim slowly while others will rest motionless along the surface. Others, like sleeping sperm whales, will float vertically in groups just under the surface to enter a deeper rest.
How long can whales hold their breath underwater?
Whales can generally hold their breath for 45 minutes to up to two hours before needing to surface, depending on the species.
Several factors contribute to this impressive feat. For one, whales can take in more air with each breath than humans can. Their red blood cells, the mechanism by which oxygen is transported in our body, also carry more oxygen than humans.
You can imagine that using oxygen wisely is crucial for long dives, so whales have adapted to slow their heart rate and divert their blood flow, and in turn their oxygen flow, away from the surface of their body so that it is conserved for dive-essential organs, such as the heart, brain and swimming muscles.
What is a group of whales called?
Many whale species are social and can be found in groups called pods.
Pods can contain anywhere from two to more than 30 individuals. Generally, smaller whales can be found in larger pods while bigger whales are often found in small pods or traveling solo. Scientists believe whales form pods for social interaction, to protect themselves from predators and to hunt for food collaboratively.
Enjoyed This Animal Trivia? Discover More Whale Facts and Information
Yes, I want to save a life!
Yes, I want to save a life!
You’ll be giving sick and injured animals the best possible care at the Center’s state-of-the-art hospital. With your gift today, you are giving a patient a second chance at life in the wild.
See Our Latest News
{"image":"\/Animals\/Wild\/Elephant seal\/cropped-images\/elephant-seal-mom-and-pup-photo-c-brian-simuro-156-0-1270-992-1748974858.jpeg","alt":"Northern elephant seal and pup","title":"The New York Times: Racing to Save California\u2019s Elephant Seals From Bird Flu","link_url":"https:\/\/www.marinemammalcenter.org\/news\/the-new-york-times-racing-to-save-californias-elephant-seals-from-bird-flu","label":"In the News","date":"2025-06-03 02:00:00"}
The New York Times: Racing to Save California’s Elephant Seals From Bird Flu
June 3, 2025
Read More{"image":"\/Animals\/Wild\/Gray whale\/cropped-images\/a-dead-gray-whalesf-bay40225photo-c-the-marine-mammal-center-53-0-1270-992-1748642560.jpg","alt":"a dead gray whale in the water with birds flying above","title":"NBC News: Six dead gray whales found in San Francisco Bay area in the last week","link_url":"https:\/\/www.marinemammalcenter.org\/news\/nbc-news-six-dead-gray-whales-found-in-san-francisco-bay-area-in-the-last-week","label":"In the News","date":"2025-05-29 02:00:00"}
NBC News: Six dead gray whales found in San Francisco Bay area in the last week
May 29, 2025
Read More{"image":"\/Animals\/Patients\/Elephant seals\/cropped-images\/es-hoffman47927-photo-by-bill-hunnewell-c-the-marine-mammal-center-124-0-1270-992-1748384535.jpg","alt":"An An elephant seal\u2019s face with long black whiskers and wide eyes emerges from the water. ","title":"Adaptations of the Deep: Seal Whiskers and Eyes","link_url":"https:\/\/www.marinemammalcenter.org\/news\/adaptations-of-the-deep-seal-whiskers-and-eyes","label":"Patient Update","date":"2025-05-28 02:00:00"}
{"image":"\/Animals\/Wild\/Other species\/cropped-images\/two-seals-playing-shutterstock-250-0-3211-2510-1602631793.jpg","alt":"two seals playing on a beach","title":"Meaningful Father\u2019s Day Gifts for Ocean Lovers","link_url":"https:\/\/www.marinemammalcenter.org\/news\/eco-friendly-fathers-day-gifts-that-give-back","label":"News Update","date":"2025-05-09 12:37:57"}
natural history