Earthworms do not have five hearts like humans do, but they do have five heart-like structures called aortic arches. These blood vessels help pump blood through an earthworm’s body, working somewhat like hearts. This is why people often say that earthworms have five hearts.

Earthworm Coloring Sheet

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Do Earthworms Really Have Five Hearts?

The answer is kind of! An earthworm’s circulatory system is different from ours, but it serves an important purpose.

Earthworms need blood to move throughout their bodies and deliver the oxygen they need to live and do their busy underground work. Instead of a heart like the one inside our chests, an earthworm has five heart-like structures called aortic arches.

Aortic arches are blood vessels that help pump blood through an earthworm’s body. Because they work somewhat like hearts, people commonly say earthworms have “five hearts.”

So, does an earthworm have five hearts? Not exactly. But it does have a unique and powerful pumping system designed to move blood through its long, narrow body.

What Is an Earthworm?

Earthworms are invertebrates, which means they are animals without backbones. In fact, earthworms don’t have any bones at all!

They belong to a group called Annelida, which includes segmented worms. If you look closely at an earthworm, you can see the ring-like segments along its body. These rings are called annuli.

Earthworms also don’t have eyes, arms, or legs. Even without these features, they are wonderfully designed to navigate their underground world.

How Do Earthworms Move Without Bones or Legs?

An earthworm’s body is packed with muscles. Beneath its skin are two sets of special muscles. Circular muscles wrap around the earthworm, while another set runs lengthwise from head to tail. Together, these muscles allow the earthworm to lengthen and shorten its body.

Earthworms also have tiny hair-like structures called setae on their segments. These bristles grip the soil as the worm moves.

With powerful muscles and tiny bristles, an earthworm can tunnel through the dirt without any arms, legs, or bones.

Why Are Earthworms Important?

As earthworms tunnel through the soil, they swallow dirt containing tiny pieces of dead plants and other organic matter. Earthworms are detritivores, creatures that eat dead or decaying things and mix them into the soil.

After digesting the soil, the remaining material passes through their bodies as worm castings.

Their tunnels also create spaces where air and water can move through the soil. As earthworms dig, eat, and tunnel, they recycle nutrients, create healthy soil, and aerate the ground to help plants grow.

Much of this important work happens unseen beneath our feet. Earthworms remind us that our work still matters, even when no one else notices.

Colossians 3:23 says, “In all the work you are doing, work the best you can. Work as if you were doing it for the Lord, not for people.”

The next time you find an earthworm, remember its five amazing aortic arches and all the important work God designed this little creature to do underground.

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