How does a hedgehog roll up?

Pretty much every time that we pick up the hedgehog animal ambassador, she rolls into a ball.

Her pointy spines stand erect, and you can't see any other part of her.

(See a video of Honey the hedgehog here.)

The reason that hedgehogs do this is the same reason that turtles will pull their appendages into their shells --- protection.

When they are frightened, or annoyed, hedgehogs will roll into a ball so that an predator will feel the full brunt of its sharp spines and will then leave the hedgehog alone.

You wouldn't want to eat something that pokey would you?

Photo of a hedgehogopens IMAGE file But how does a hedgehog do it? If you and I tried to roll into a ball, you could still see our arms and legs. However, when Honey the hedgehog rolls up, you can't see anything but spines!

When threatened, a hedgehog contracts two muscles that pull in opposite directions. Think about pulling a drawstring bag, when you pull the strings in different directions, the opening of the bag closes up. When the hedgehog contracts its muscles, they pull on the ball-like base of its spine, and that spine is pulled from a relaxed position to standing straight up.

The muscles pull different spines in different directions, so they crisscross and form a nearly impenetrable barrier.

Then its belly and back muscles help it tuck its head, legs and tail inside extra skin.

Photo of a hedgehog without spinesopens IMAGE file

This hedgehog has a condition that caused it to lose its spines, but it gives a glimpse into how it uses muscles and extra skin to roll into a protective ball.

Fun facts about hedgehog spines

  • Hedgehogs can climb but struggle to get back down. Sometimes they will simply roll into a ball and drop, allowing the spines to cushion the fall. Wild hedgehogs have been seen dropping from up to 20 feet this way.
  • Hedgehogs can add extra protection to their spines by licking poisonous plants that they're immune to and then making a frothy saliva in their mouths. They then lick their spines, spreading the plant's poison, to become even more irritating to predators.
  • After birth, hedgehog spines are short and soft. They will harden, and then they will lose their spines as they age and grow a new set of spines for their adults bodies.

Five differences between hedgehogs and porcupines

Many people ask if the hedgehog animal ambassador at the Dickinson County Nature Center is related to a porcupine. However, hedgehogs and porcupines aren’t actually related at all. There are 17 different species of hedgehogs, and their closest relations are actually shrews and moles. There are more than two dozen species of porcupines in the Read More »

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Baby hedgehogs lose their spines

Babies lose baby teeth, and so do baby animals — including baby hedgehogs, like the nature center’s animal ambassador Luna. However, hedgehogs also lose something else as they grow — their quills! Baby hedgehogs are born with spines, but at that time their skin is swollen and covers their spines so that they do not Read More »

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How cottontail rabbits survive the winter

My husband and I keep opening up our mud room door to see an eastern cottontail rabbit darting away, and any fresh snow reveals bunny tracks on our concrete patio. “Why does it keep sitting here?” My husband asked me. “I don’t know, maybe trying to keep out of the wind?” We started to discuss Read More »

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7 cute cottontail facts

The Dickinson County Nature Center’s bunny animal ambassador, named Bindi, is actually a pet rabbit species. However, this mini rex looks quite a lot like the native rabbit in Iowa, the eastern cottontail. They both have a fluffy white tail, long ears, a brown coat with lighter colors in the undercoat and dark eyes. There Read More »

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1 Comment

  1. Glen S. Keith on August 21, 2019 at 5:08 pm

    I lived in the northern part of Switzerland for a few years and there were lots of hedgehogs..we seemed to encounter them in the winter, and our Jack Russell (leashed) would get vocal , and ‘boop’! into a ball. If it was quiet it would make a noise, not aggressive. We didn’t torment, when we realized there route, we moved down and watched the odd one head off to doo hedgehog stuff