Image Copyright Collin Hutton

The response to my post about the Mad Hatterpillar of Australia was amazing! Apparently animals that wear their former heads as hats are fascinating.

I mentioned that some North American caterpillars also build themselves hats out of discarded heads, and I’ve managed to find some cool photos of those as wel. Harrisimemna trisignata is a distant relative of the Australian species.

A commenter described it as “falling out of the ugly tree and hitting every branch on the way down.” That seems a little harsh, but I guess hatters gonna hat. It certainly is true that the zombie heads have a bit of a sinister look.

This caterpillar also has some strange behavior to go with its strange head capsule hoarding. The always awesome Weird Bug Lady is studying this species, and thinks it is a bird dropping mimic. Complete with chunks and white streaks mimicking uric acid in a bird flop. They also have some strange behavior:

“They shake! They shake when I open the container, when I breathe on them, when I talk to them, when I touch them, when I look at them the wrong way. I can just imagine a potential parasitoid, like a tiny wasp, trying to land on that caterpillar… between the shaking and the head capsule whipping, I doubt it would stick around.”

Here, have a look:

The caterpillars chew into wood to pupate (!), and they roll the wood up into neat little balls and then throw them (!!).  The adults of this moth look rather like they are carrying a QR code.

Many more cool photos of the caterpillar by Colin Hutton here.

Posted by Gwen Pearson

Writer. Nerd. Insect Evangelist. Have you heard the good news? BUGS!


  1. […] Hatters gonna hat: another Mad Hatterpillar species […]

  2. Fascinating stuff! Both the photos and the video showcase really neat adaptations. thanks!

  3. Reblogged this on lab ant and commented:
    I really like this blog!

  4. Judhajit Dasgupta July 12, 2013 at 5:13 pm

    Thank you Bug G. Membracid, for bringing this to us. I had seen one similar behaviour — piling up of discarded skins of its own by an insect and carrying the pile on its body. It was by the larvae of a Tortoise Beetle. After hatching out the larvae live as a cluster beneath a single leaf of a plant of Ipomea sp. The discarded skins are arranged similarly as the head capsules are arranged in the ‘Hatterpillar’ — latest one at the bottom of the stack (naturally!). Thus the stack is thick at the bottom and tapers upward.
    But the stack is placed not on its head, but at the rear end of its body and held vertically up. Thus it actually looks like a tail and the insect reminds a tiny scorpion. Moreover the larva carries some thorny projections all over its body — the tail is actually stuck to one or a couple of these thorns. The capsules retain the thorny appearance. Thus as the insect grows, it looks like some formidable stinging creature! To make them more scary all of them wag these thorny ‘tails’ in unison even if the leaf is merely touched or someone breathes on them.
    I have some photographs, but those are not digitised. May be in future I can share them.

  5. I am so excited to find another bug girl.. I am going to spend more time on your site than mine (www.abuggirl.com)

  6. What a fascinating post! Thanks for sharing that video. I haven’t read the other Mad Hatterpillar post yet. But, I definitely will now.

  7. […] your heads! That’s precisely what this one caterpillar does. It shakes All of its old […]

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