Are all animal hearts the same size?

It’s Valentine’s Day! Candy hearts are in stores in all different sizes. Tiny red hearts that taste hot. Small candy hearts with messages on them. And, large chocolate hearts with nuts in them.

What about the real hearts of animals? Are they all the same size? No, they are not.

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The blue whale is the largest animal. It also has the largest heart. A blue whale’s heart weighs about 400 pounds. That’s how much a large refrigerator weighs!

The smallest heart belongs to a tiny wasp (a small insect that can fly). The heart runs along its back. It is so small, you need a microscope (a machine that makes small things look bigger) to see it!

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What about the size of your heart? A child’s heart is about the size of a fist.

What Can You Do? Why do you think animals have hearts of different sizes?

Photo Credit: decade3d – anatomy online/Shutterstock