Image of the Day: Turtle Ant Soldiers

Big heads come in handy when the social insects are tasked with defending their nest.

Amy Schleunes
Amy Schleunes

A former intern at The Scientist, Amy studied neurobiology at Cornell University and later earned her MFA in creative writing from the University of Iowa. She is a Los...

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Mar 12, 2020
Turtle ant soldiers and workers bring their large heads together to create a functional barrier at the entrance to their nest.

Turtle ants (genus Cephalotes), which use their “elaborately armored heads as living barricades” to defend the entrances to large nests, have experienced repeated changes and reversions to their head size over the course of evolution, according to a study published on March 9 in PNAS that compared the evolution of head size in various Cephalotes species.

S. Powell et al., “Trait evolution is reversible, repeatable, and decoupled in the soldier caste of turtle ants,” PNASdoi:10.1073/pnas.1913750117, 2020.

Amy Schleunes is an intern at The Scientist. Email her at