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Whoops! A Millipede Toddler Learns to Walk

Ivan the Terrible? He was pretty terrible. Alexander the Great? Pretty great. (At least at conquering.) Their names seem to fit their deeds. But here’s a name that doesn’t: Millipede. I’m talking about those many-footed little guys you sometimes see on the forest floor chewing on leaves, the ones that sometimes curl up into tight little spirals when you disturb them.

Picture of an orange and black millipede rolled up into a ball on a green leaf in Indonesia
Glomeris (Glomeris sp) millipede rolled into a protective ball, Kalimantan, Indonesia
Photograph by Cyril Ruoso, Minden Pictures

Yes, millipedes have feet, lots of them, so I’m good with the last syllable, ped, Latin for foot. But the first syllable, milli, Latin for a thousand? That’s a crazy exaggeration. Millipedes don’t have a thousand feet. Not even close.

The Embarrassing Truth About Millipedes

It turns out the world record holder, the most leggy millipede ever seen by scientists, says zoologist Rowland Shelley, is a little guy found in San Benito County in California in the 1920s. It had 750 feet. That’s a lot, but it ain’t no thousand. “It would have [had] to grow by another one-third … to become a true ‘thousand legger,’” Shelley says.

The sad fact is most millipedes (and there are thousands of varieties) are more “centi” than “milli”; they have fewer than a hundred feet. So as busy and as useful as they are (this time of year they are busy cleaning up our yards munching, munching, munching leaf bits), they aren’t anywhere as footy as they seem, and yet … here’s the surprise: When you think about millipedes too much, as I did today, you discover there’s an early moment in a millipede’s life when the most curious thing about it is not how many, but how few feet they have.

I’m talking about what a millipede looks like on its birthday—when it hatches and joins the world with its original set of baby legs. Say hello to a millipede toddler …

Illustration of a millipede toddler
All Drawings by Robert Krulwich

Millipedes are built in segments. Like repeating Lego pieces. Each segment (after the first few) is a fused combination containing two pair of legs, like this …

Illustration of a segment of a millipede

Put them together, and you have a working animal.

Illustration of a millipede

As a millipede grows, it molts, throws off its outer hard cuticle, or skin, and adds segments, so over its life, it adds more and more parts with more and more legs.

Photograph of the underside of a reddish-colored millipede, showing its many legs
Photograph © Bill Hilton Jr., Hilton Pond Center

But when it’s a hatchling, a baby, it starts with a head (no legs), a helmetlike segment (no legs), and then maybe a preliminary segment (one pair of legs) plus a very few regular segments—which means it starts life with astonishingly few limbs.

Count the feet on this birthday boy (thank you Petra Sierwald, zoologist at the Field Museum in Chicago)—and you will see, Sierwald figures, roughly “six or eight” feet.

Illustration of a baby millipede, showing only six legs

That’s not a lot.

Millipedes don’t hop. They can’t slither. They don’t walk like we humans do, one foot in front of another. “They move several legs together,” Sierwald says. “It’s a coordinated movement,” and that requires legs to work in teams. Three legs forward, three legs back—that sort of thing.

So how does a baby with six to eight legs create leg teams? Do they have enough legs to move, or do they spend their first weeks stockstill, staring at the world? “I don’t know,” Sierwald told me on the phone. “We have a bunch of toddlers here at the museum. We’ve never looked to see, but maybe we should.”

I think they should. Sierwald found an old paper by Danish zoologist Henrik Enghoff, who says most millipede babies stay put for their first few weeks, waiting for their next molting. Some though, with eight legs, do venture about, but either way, what we have here is an animal famous for its legginess—too famous, really—beginning life with a leg deficit. This makes me wonder: Do toddler millipedes fall over? Do they bump into roots? Get toppled by buttercups? Do they behave like baby humans and have to learn how to get places?

Just the thought of it makes me smile.

Drawing by Robert Krulwich

I got thinking about millipedes while reading Sue Hubbell’s Waiting for Aphrodite; Journeys Into the Time Before Bones. She describes herself as a giant “stumbling around in the world of little things,” which include sponges, sea urchins, bees, spiders, and, to my delight, these many-footed millipedes who’ve “been creeping around on this planet” for 400 million years.

8 thoughts on “Whoops! A Millipede Toddler Learns to Walk

  1. As usual Robert, your article Great! In spanish we call milipedes “cienpies”, the translation would be “houndred feet”, i think it´s more accurate than the name in english, considering the number of legs they have.

  2. If a millipede wants to kick another millipede in the shins, does he kick with all of his legs on one side at once, or does he stand still and kick with his legs one at a time?

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