I can’t be the only one who’s ever looked at a bar of soap and thought “it smells good, it looks good, it must be delicious.” My youthful optimism died with the horrifying realization that you can’t always believe your eyes and nose when determining what will make a tasty afternoon snack. Fortunately, this was a lesson I only had to learn once, and to this day, I have a instant repulsion for foods in a certain tint of pastel lavender.

Nature has its own form of the appealing-but-unappetizing which acts as a species-wide survival strategy called aposematism.

A monarch butterfly perched on a bucket

Take the monarch butterfly. Unlike other insects such as the grasshopper which usually sport coloration matching their chosen habitat, the monarch butterfly takes a lesson in subtlety from Sasha Velour (though the fabulous monarch shown above is actually a king, you can tell by the black dot on each hind wing).

Though it seems counterintuitive, this bright and distinct coloring actually acts as an overall advantage for the monarch butterfly as a species. Due to their diet of milkweed as caterpillars, monarch butterflies retain a level of toxicity that can make predators who ingest monarchs sick.

This usually plays out in nature like so: a bird sees a conspicuously-colored monarch and decides to take an early lunch, the bird becomes ill shortly after eating the monarch, and now, the bird now associates the bright wings of the monarch butterfly with sickness and avoids all monarch butterflies it may see in the future.

If you think back, you may be able to recognize this phenomena of warning coloration—aposematism—in other species. From poison dart frogs to coral snakes, nature has developed its own form of distinctly-colored, snack-shaped, disgusting-to-eat soap that leaves a lasting impression in the minds of hungry foragers.

Though there are many reasons animals are pushed to one coloration or another (I’ll have to go through them some day, they’re fascinating to consider), aposematism provides a unique option for sci-fi and fantasy world builders looking to add a bit of elegant and unsuspecting peril to their settings.


The Monarch is a Poisonous Butterfly

Multiple, recurring origins of aposematism and diet specialization in poison frogs