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Earthworm Love is Cuddly ... and Complicated

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Earthworms know a thing or two about romance. They cozy up with a mate inside tubes of slime, then follow a series of intricate steps to make cocoons full of baby worms.


Earthworm love.

It’s cuddly … and complicated.

From the start, the earthworm is built for romance, with four or five pairs of hearts.

Finding a match, though? That’s a challenge for these mostly solitary animals.


They go out looking when they’re a few months to a year old, and they’ve grown this fleshy, saddle-shaped patch, called a clitellum. They’re now mature enough to get down to business.

Tube-shaped invertebrate seeks mate to share loamy soil and good times.

The earthworm follows tastes and smells through dirt or leaf litter to find its valentine.

It crawls around by anchoring its body with these bristles called setae, then pushing forward with its muscles.

Along the way, it fuels up on bacteria and tiny fungi in the soil and leaves, sucking them in with its mouth.

Such a luscious … lip?

Every earthworm has some non-negotiables: Must breathe through iridescent skin. Must want kids.

But being male or female is not one of them. All earthworms are both. They’re hermaphrodites, which automatically doubles their chances of finding a mate.

When they do, they waste no time.

Side by side, they surround each other with rings of slime they exude from their skin, bodies pointing in opposite directions.

And they embrace with these flaps on their clitella.

They can canoodle like this for an hour, swapping sperm.

It travels outside their bodies, here, where they press up against each other, and flows between these segments into storage sacs inside.

But their tender act has a dark side. As they do the deed, the earthworms stab each other with their pointy setae. Those wounds mean the injured lovers won’t be hooking up with others anytime soon. Jealous much?

After they’ve parted ways, each earthworm produces a sheath with its clitellum and shimmies it down its tubular body. The protein-rich ring moves over tiny holes where it gathers eggs and some of the collected sperm.

Then, it slips right off the worm and becomes a cocoon.

Baby worms flourish inside, growing beating hearts that one day they’ll give to their special someone.

Hi! Deep Look wants to launch a newsletter for you, and we want you Deep Peeps to decide what goes in it. So, please take our survey — link in the description.

But first, don’t miss our episode on worm *lions.* The fearsome wormlion larva ambushes prey at the bottom of a sand pit, then flicks the carcasses away.

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