Nature Blows My Mind! Caterpillar mimics snake behavior to scare predators (Video)

D. H. Janzen & W. Hallwachs
© D. H. Janzen & W. Hallwachs

A well-known survival tactic in the natural world is an organism mimicking the appearance of something else in order to fool predators. Leafy-looking insects are one example, and for the Hemeroplanes triptolemus moth, survival of its caterpillar form means disguising itself as a snake!

D. H. Janzen & W. Hallwachs© D. H. Janzen & W. Hallwachs

Hemeroplanes belongs to the Sphingidae family, found in many parts of South America, Africa and Central America. Upon closer inspection, however, one will see that this 'snake' is abnormally short in length; and while its topside looks pretty non-descript, the Hemeroplanes caterpillar has the ability to put on a snake disguise at the moment it feels threatened, according to Tom Hossie over at Caterpillar Eyespots:

The caterpillar does a great job of mimicking a snake behaviourally as well. It is actually throwing itself backwards and twisting to reveal its underside which is hidden when the caterpillar is at rest. The anterior (head-end) body segments of the caterpillar inflate to form a diamond-shaped head, when fully inflated the “eyes” of the snake-like false head seem to open.

D. H. Janzen & W. Hallwachs© D. H. Janzen & W. Hallwachs

D. H. Janzen & W. Hallwachs© D. H. Janzen & W. Hallwachs

To scare predators off quickly, this harmless caterpillar will also sometimes move its body like a striking snake, despite the fact that it doesn't have fangs nor venom. Hossie explains that Hemeroplanes triptolemus is probably the most well-known of caterpillars with distinctive 'eyespots':

Many animals have conspicuous eye-like spots on their body. In most animals these ‘eyespots’ are thought to intimidate predators from attacking or deflect the predator strikes away from vulnerable body parts. That ‘eyespots’ could help prey by resembling the eyes of a predator’s own enemies is thought to be particularly true for butterfly and moth caterpillars. Caterpillars with eyespots are often cited to be snake mimics that startle attacking birds which mistake them for dangerous snakes. Despite widespread acceptance, this phenomena is surprisingly understudied.

D. H. Janzen & W. Hallwachs© D. H. Janzen & W. Hallwachs

Here is a photo of Hemeroplanes triptolemus fully grown and looking nothing like a slithery snake:

Shawn Hanrahan Shawn Hanrahan /CC BY-SA 2.0

Check out more info and photos of this remarkable little caterpillar over at Caterpillar Eyespots and the Area de Conservación Guanacaste (ACG) websites.

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