This is what really happens if you cut a worm in two

This is what really happens if you cut a worm in two

Inside the strange science of animal regeneration

Photo credit: Getty

Published: March 30, 2025 at 3:00 pm

Never cut a worm in half lengthways. It’ll most definitely not regenerate or, indeed, survive. Should a worm accidentally be sliced widthways, however, perpendicular to the length of its body, it might well live to wriggle another day.

“Most have some powers of regeneration,” says Emma Sherlock, senior curator of free-living worms at London’s Natural History Museum, “but this depends on the species.”

Earthworms, for example, can regrow their tails, but the ‘Wolverine Award for Best Regenerative Powers’ goes to the tiny planarian flatworm, which can regrow its whole body from just a tiny sliver of tissue.


This article is an answer to the question (asked by Dr Keith C Marshall, via email) 'If a worm was cut lengthways, would it regenerate?'

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About our expert

Emma Sherlock is the senior curator of free-living worms at the Natural History Museum in London, UK. She has been published in various scientific journals including Zootaxa, Marine Biodiversity and London Naturalist.

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