Blue whales are the largest animal ever known to have lived, even larger than the dinosaurs who once roamed the Earth. In fact, the longest blue whale ever measured was 111 feet long — approximately the length of three school buses parked end to end.

Scientists have determined two causes for the blue whale’s massive size. First, the blue whale lives in the ocean. Since the ocean covers more than 70 percent of the Earth’s surface, whales have plenty of room to grow and swim.

Another contributor to the blue whale’s size is a phenomenon called “zero gravity.” If you’ve ever noticed that feeling of being weightless as you float in a swimming pool, you’ve experienced zero gravity, too!

Unlike humans, the blue whale does not rely on its skeleton to support its huge body. Instead, the whale relies on zero gravity and buoyancy to keep its body afloat.

Despite its huge size, the blue whale’s diet consists almost entirely of krill — small shrimp-like crustaceans. The whale gathers thousands of krill at a time by sucking enormous mouthfuls of seawater through a special mouth filter called a “baleen.” As the whale closes its mouth, seawater is flushed out, leaving krill and small fish behind for the whale to swallow.

Coming across such a giant creature in the ocean may seem scary, but blue whales are harmless to humans. In fact, they even have some things in common with us!

Blue whales are warm-blooded mammals. Unlike fish, they must breathe air.

Research also indicates that blue whales are highly social and very intelligent. They even have their own form of language used to communicate with other whales. Listen to what they have to say!

Here are some other fun facts about blue whales:

  • The heart of an adult blue whale is the largest of any mammal.
  • A blue whale heart can weigh up to 1,300 pounds and is the size of a Volkswagen Beetle.
  • The tongue of an adult blue whale is approximately the same weight as an adult elephant.

What about baby blue whales? Here are some fun facts about blue whales’ “little” ones:

  • At birth, a blue whale calf is about the size of a hippopotamus.
  • A baby whale can drink up to 100 gallons of milk every day during its first seven months of life.
  • With that kind of diet, it should come as no surprise that a baby whale can gain up to 200 pounds a day.


18 Join the Discussion

1 Star2 Stars3 Stars4 Stars5 Stars  (55 votes, avg. 4.31 out of 5)
    • Hello, “Wonder!” This was an early Wonder of the Day®, when Wonderopolis was new and most of our AWESOME Wonder Friends didn’t know about us yet! Thank you for visiting some of the very first Wonders and leaving us comments today! :-)

    • Hmmmm. Let’s see…we think you are our Wonder Friend, Aidan! Thanks for sharing your comment with us today! We appreciate you letting us know you would like to see a future Wonder about cyber whales. Here is another Wonder about whales we think you might really like to explore:

      Wonder #489 – What Is a Narwhal?


  1. Hi my name is Maddy and in school I am learning about whales and I want to know what do whales eat what do whales do for a living and what do whales do to communicate? Can you tell me at least one because I love whales and I want wonderopolis to tell me everything you know about whales. So can you tell me everything you know about whales and what does pods look like and do whales actully swim in pods and why do they swim in pods? Do whales like the winter or do the whales like the summer better? Why do whales migrate to shallow water to clean and some whales have babies in shallow water?

    • HELLO, Maddy!! We are SO excited that you love whales as much as we do! WOHOO!

      We bet you’ll enjoy another whale Wonder from the past, too!

      Wonder #661– Do All Whales Have Bumpy Skin? :)

      We are very proud of all the WONDERing you have been doing, too! We Wonder if you can do some research of your own to find out why whales travel in pods, where they like to spend their summer vacations and if they prefer shallow water! We think you’re doing a GREAT job! :)

  2. The video was so exciting. I cannot wait to see one in real life. I have a question do you know about the fin whale if you say no then they’re extinct. In my opinion whale shark are 2-3 in the biggest whale. Even if it not a whale. Very interested to learn more. Hope you put more wonder about animals.

  3. The biggest whale is so majestic in its own way. The way it glides through the water gracefully without a sound. Also the way it eats it inhales its food and then it has a flap of skin that can adjust to the size of food it takes. Long may they live! :)

    • Hi there, Wonder Friend Kate! We are so excited that you have enjoyed WONDERing with us about whales today! You have done a great job of describing your favorite things about whales– how it swims, lives and eats! Great work! We hope you have a SUPER day! :)

    • Thanks so much, Sifelani! We are so excited that you enjoyed this Wonder with us! Whales sure are WONDERful! :)

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>


  • Wonderopolis on Facebook
  • Wonderopolis on Pinterest
  • Print

Have you ever wondered…

  • What is the largest animal?
  • How big is the biggest whale?
  • What does the biggest whale eat?

Wonder Gallery

Wonder #42 - Blue Whale Static ImageVimeo Video

Try It Out

Whales use special sounds to communicate with one another — and you can, too!

Morse code is a method of sending information as a series of clicks. When using Morse code, each letter of the alphabet is represented by a different pattern of dots and dashes.

Try your hand at Morse code by checking out this Morse Code Translator. By typing a message into the Input box and clicking Translate, the Morse code translator will show you how your message is written in Morse code. Then click the Play button to hear how your Morse code message sounds.


Still Wondering

Check out National Geographic Education’s Crittercam: Tiger Sharks video to explore the warm, summer waters of Shark Bay, home to thousands of tiger sharks.

Wonder Categories/Tags


Wonder What’s Next?

Wondering what Wonderopolis has planned for tomorrow? We’re taking out the trash! Get ready to go behind the scenes with paper, plastic and glass. Meet us curbside in the morning for a wonder that has the power to make treasure from trash.

Upload a Photo or Paste the URL of a YouTube or SchoolTube Video.