Mammals that chose ants and termites as food almost never go back

Imagine a diet consisting solely of ants and termites—while it sounds bizarre, this has been the reality for several mammal species worldwide. Over the past 66 million years, mammals have independently evolved to embrace this unusual diet not just once but at least a dozen times. From anteaters and aardvarks to pangolins and aardwolves, these myrmecophages, as they are known, have developed unique adaptations. These adaptations include the loss of most or all teeth and the development of long, sticky tongues, enabling them to consume vast quantities of insects daily—sometimes tens or even hundreds of thousands. A recent study has shed light on this remarkable phenomenon, revealing that the specialization for eating ants and termites has emerged independently in various mammal lineages throughout the Cenozoic era. Thomas Vida, the study's lead author and a researcher at the University of Bonn, expressed surprise at the number of distinct origins for this dietary habit. He noted that these origins align closely with the growth patterns of ant and termite colonies during the same period. To investigate how frequently and when mammals developed a preference for these insects, the researchers meticulously identified species that are strictly reliant on ants and termites for sustenance. This process involved reviewing nearly a century of research, including numerous natural history papers and zoological texts. The researchers analyzed data from 4,099 living mammal species, categorizing them into five dietary groups: strict myrmecophages, general insectivores, carnivores, omnivores, and herbivores. With this comprehensive dataset, they employed statistical models to trace back and reconstruct the likely diets of these mammals' ancestors, revealing the intricate relationship between mammalian evolution and the availability of ant and termite resources.