The natural world is filled with flora and fauna whose life and adaptation techniques continue to fascinate humans as we continually discover them.

In the forests of Costa Rica, colonies of ants have been harboring a secret that probably even they were unaware of. A beetle species masquerading as an ant abdomen to hitch a free ride was just discovered by a team of researchers.

Nymphister kronaueri

Fondly named after field biologist and army ant researcher David Kronauer, the newly observed beetle species was discovered when researchers were puzzled by one of the ants they had collected in their sample.

The ant in question looked normal from above, but upon further inspection, they noticed that the specimen seemed to have two abdomens. However, the truth was far more interesting.

"When we shook the vial the beetle detached and expanded its legs and antennae — that is the moment we realized we had discovered something new here," said Christoph von Beeren, co-author of the study.

The stealthy N. kronaueri is highly specialized as it uses the strength of the army ant's colony for survival. Though little is still known about this species, researchers have observed that the beetle uses its strong mandibles to attach itself between the ant's narrow waist just between the thorax and the gaster.

As they do, their dark reddish brown color, almost identical to the army ant's, camouflages them to other ants in the colony. Researchers also found that the N. kronaueri attaches itself only to ants of a certain size.

Army Ants and Their Followers

Army ants are different from other ant species in a very particular way. Unlike other ant species, they do not build permanent nests in trees or underground, but instead they continuously travel from one point to another. They build only temporary nests from their own bodies to shield their queen.

In some species, the colony tends to remain stationary for quite a while before moving on to the next location, making them perfect vessels for the N. Kronaueri and other such myrmecophile fauna.

As important arthropod predators, army ants play an important role in tropical forests. As such, they play host to a number of myrmecophiles, which are other arthropod species that take advantage of the colony's strength for survival. In many cases, arthropods such as millipedes, mites, beetles and phorid flies display excellent adaptation techniques in order to take advantage of the army ants' lifestyle and strength.

Though some of them resort to chemical and morphological mimcry, little is still known about the N. kronaueri's relationship with its army ant host.

Given the nature of the discovery of this beetle species, authors of the study acknowledge that there are still many species with incredible adaptation strategies to discover. After all, they wouldn't have discovered the species if they didn't wonder why this one ant had two behinds.