Watch Ants Enter a Cultish ‘Death Spiral’ Vortex Without Explanation

Written by Kirstin Harrington
Published: September 20, 2022
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Ants are tiny, curious critters that most humans don’t know a lot about. They’re capable of incredible things, such as using their own bodies to build a bridge or to float across bodies of water. Just like other insects, they can display strange behaviors as well. One of these peculiar behaviors is called an ant mill, and well, you just have to see it to believe it.

Army ants, unlike other ant species, do not build lasting nests and are constantly moving while they are living, making the “ant death spiral” a phenomenon that appears to solely affect these ants. Usually, they follow the smell trails left by the ants in the swarm that came before them. These ants are blind and rely solely on smell to find their way around.  

The death spiral is a useful metaphor for highlighting the dangers of follow-the-leader behavior in any culture and serves as an illustration of what occurs when the colony as a whole is diverted.

Army ants have earned a reputation for being fierce. These South American ants hunt frequently, killing any unwary birds that cross their way in addition to the insects and arachnids that are their primary food. A small bird can be killed by workers in as little as four stings. They are smart animals but can be deceived by their own instincts just like anything else. 

Since the ants build up trails as they go, if one of them accidentally crosses a previous path, the others can simply follow it around and reinforce the trail together. Large spinning vortices or small, clean circles may result from this. Each ant needed more than two hours to finish the circle in the largest known ant mill, which was 1,200 feet across! 

A Sight to Behold

From above, it almost appears as if it’s a hurricane made out of ants. It’s a wild and rare sight to see. One comment under the video reads, “Before we knew it we became a hurricane.” Ant mills can start out of nowhere and quickly escalate to something fatal for the insects

Although ant milling has likely existed for ages, it was only discovered by science in 1936 when ant scientist T.C. Schneirla discovered one that had several hundred ants and lasted for a full day. They continued regardless of how hard it rained. Most of them had passed away before morning, yet a handful remained in the circle weakly and dangerously close to death.

​​While evolution provided the ants with an effective approach for coexisting, it may also have left them with leftover behavior, a “pathological” habit that can be seen as the imprints left by the evolutionary trajectory where these ants have been bound. It’s the end of the journey when that trap likewise locks these little critters in a death spiral.

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The photo featured at the top of this post is © NOTE OMG/

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About the Author

Kirstin is a writer at A-Z Animals primarily covering animals, news topics, fun places, and helpful tips. Kirstin has been writing on a variety of topics for over five years. She has her real estate license, along with an associates degree in another field. A resident of Minnesota, Kirstin treats her two cats (Spook and Finlay) like the children they are. She never misses an opportunity to explore a thrift store with a coffee in hand, especially if it’s a cold autumn day!

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