Leaf-cutting worker ants might look like they’d be helpless against an enemy soldier ant many times their size. But some of the smaller ants have a secret: Their entire body is coated with a thin but tough layer of mineral armor.
It’s the first time that this type of external, whole-body mineralization has been found in an adult insect, researchers report online November 24 in Nature Communications.
“I found rock ants,” evolutionary biologist Hongjie Li recalls telling his colleague, evolutionary biologist Cameron Currie, when the first experimental results of the hard coating came in. “I can still feel the excitement now,” Li says.
The discovery was serendipitous, says Currie, of the University of Wisconsin–Madison, who has been studying leaf-cutting ants for more than 20 years. His lab had been examining interactions between ants and their external microbes, which are thought to play a pivotal role in the ants’ farming