Mammals
What do you, a giant grizzly bear, and a tiny flying bat all have in common? Join Bill Nye the Science Guy as we explore the amazing animal family that we belong to. Discover what it takes to be a mammal, from having hair to being warm-blooded, and see how mammals have adapted to live everywhere from the deepest oceans to the open skies!
Welcome to the Mammal Family
Yes, for a little while! Bill Nye the Science Guy uses this exact experiment to show how a mammal's hair or fur acts just like that towel. It traps heat inside to help keep the animal warm when it is freezing outside.
Because it is packed with energy! Mammal milk contains water, fat, sugar, protein, vitamins, and minerals. It is perfectly formulated with everything a growing body needs to survive and get bigger.
Put Your Instincts to the Test
Think about how mammals survive and function. Pick an answer for each question, then see if your instincts were right.
It drinks milk! One of the most important defining traits of all mammals is that mothers produce milk to feed their young. This rich food provides everything a growing baby needs!
It stays almost exactly the same! Mammals are warm-blooded, meaning their bodies automatically burn food energy to maintain a constant internal temperature, no matter how cold it gets outside.
Understanding the Science
Tap each card to uncover the unique traits that define a mammal and the incredible ways they adapt to their environments.
Key Concepts
Mammal
Tap to learn moreA specific type of animal that is warm-blooded, has hair or fur, and feeds its babies milk.
Warm-Blooded
Tap to learn moreThe ability of an animal to automatically maintain a constant internal body temperature regardless of the outside weather. This bodily process requires a massive amount of food energy.
Hair and Fur
Tap to learn moreA unique physical feature found only on mammals that helps trap body heat and keep them warm even in the freezing cold.
Mammary Glands
Tap to learn moreSpecialised organs that allow female mammals to produce nutrient-rich milk to feed their newborn babies.
Live Birth
Tap to learn moreUnlike most reptiles, amphibians, or birds that lay eggs, the vast majority of mammals give birth to live babies that develop safely inside the mother.
Nocturnal
Tap to learn moreAnimals like bats that are active during the night and sleep during the daytime. They often use keen senses like smell and hearing to navigate.
True Flying Mammals
Tap to learn moreBats are the only mammals capable of true flight. Their wings are actually modified hands with long, thin finger bones covered in a flexible membrane of skin!
Marine Mammals
Tap to learn moreMammals like whales, dolphins, and walruses that spend their entire lives in the ocean. Even though they live in the water, they are still warm-blooded, have hair, and must breathe air.
Try It: The Mammal Metabolism Lab
See how a warm-blooded body reacts to extreme temperatures!
Instructions: Press Start Lab. Adjust the outside weather and watch the bear's internal energy core. If it gets freezing cold, listen to the winter wind howl as the bear rapidly burns calories to stay warm. Hit the Feed button to replenish its energy!
STATUS: PAUSED
Apply Your Knowledge
Let us see if you can correctly identify the unique vocabulary that classifies an animal as a mammal.
Match the Concepts
Click a scientific term to select it, then click the matching description to place it.
Real-World Challenge
If a bat flies through the night sky and a walrus swims in the freezing ocean, why are they both classified in the exact same animal family as a dog or a human?
What Has Changed Since This Episode Aired
This episode originally aired in the mid-1990s. Since then, our understanding of biology and genetics has expanded significantly!
Updated: Today, scientists classify naked mole rats as the only known cold-blooded mammals. They completely lack the ability to regulate their own temperature, relying entirely on the warmth of their underground tunnels and huddling together!
Updated: Yes! Modern medical researchers have discovered that vampire bat saliva contains a powerful chemical that stops blood from clotting. Scientists have actually synthesised this into a medicine to help treat humans suffering from dangerous blood clots and strokes.
Updated: Thanks to modern fossil discoveries and DNA testing, scientists now know that mammals actually coexisted with dinosaurs for millions of years. However, these early mammals were mostly tiny, shrew-like creatures that hid in the shadows and were primarily nocturnal to avoid being eaten by large predators.
Test Your Understanding
Answer these 10 questions and get instant feedback. How many can you get right?
Results
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Reflection
Why do you think mammals need to eat so much more food every single day compared to cold-blooded reptiles like snakes or lizards?
Episode Discussion
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