Book 32, Question 43 · Video
Why are reptiles called cold-blooded if their blood isn’t always cold?
“Cold-blooded” is an old way to say that a reptile’s body temperature depends on the world around it. A lizard sitting in the sun can have blood that is warm, even warmer than yours. Scientists prefer the word ectotherm, which means “heat from outside.” Birds and mammals are endotherms, making heat inside. Both ways work well for staying alive.
Read the full answer →Watch on YouTubeSee the series on Amazon
What Crafty Clover says in this video
Intro
Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why are reptiles called cold-blooded if their blood isn’t always cold?
The Big Idea
People call reptiles cold-blooded. But a sunbathing lizard can be warm! Why the funny name?
An Old Name
Step one: An Old Name. Cold-blooded is an old way to say that a reptile's body temperature depends on the world around it. It doesn't mean its blood is always cold.
Warm Blood Sometimes
Step two: Warm Blood Sometimes. A lizard sitting in the sun can have warm blood. Sometimes it's even warmer than yours!
Better Words
Step three: Better Words. Scientists prefer the word ectotherm, which means heat from outside. Birds and mammals are endotherms, making heat inside. Both ways work well for staying alive.
A Closer Look
Let's take a closer look! Outside heat. Inside heat. Warms reptiles. Warms mammals.
Quick Facts
Quick facts! Ectotherm means outside heat. Birds are endotherms. Basking lizards can be warm. Both ways work well.
Think Like a Scientist
Now, think like a scientist! Make two signs: heat from outside and heat from inside. Gather pictures of a lizard, a dog, a turtle, and a robin. Sort each picture under a sign. Add more animals. Which group is bigger?
Outro
Cold-blooded is an old name meaning a reptile's temperature depends on its surroundings, but a basking lizard can have warm blood. Scientists say ectotherm, heat from outside, while birds and mammals are endotherms. Science is amazing! Remember, every big discovery starts with a small question. Keep looking, keep learning, and keep asking why! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!