🐝 When digger bees make their nests in bones!

Bees raising their young in the cavities of fossilized bones: this is precisely the unexpected scene discovered by paleontologists in a cave on the island of Hispaniola, where they unearthed the first fossilized bee nests built inside ancient animal remains.

Within the Cueva de Mono, in the Dominican Republic, scientists found thousands of fossils of a rodent named hutia. These bones were accumulated over generations by giant barn owls. Long after the disappearance of these predators and their prey, digger bees moved into the emptied tooth sockets and other cavities to establish their broods.


At first glance, the researchers thought of wasp nests, following a similar observation during previous excavations. However, a meticulous examination revealed a smooth surface inside the cavities, a typical signature of bee nests. These insects indeed apply a waxy substance to waterproof their homes, unlike wasps which use a rough mixture of saliva and fibers.

This initial misunderstanding led to a more thorough investigation. After consulting entomology experts and analyzing the cave's stratigraphy, the paleontologists found that the bees had also nested in the pulp cavity of a sloth's tooth and in a hutia vertebra. It even happened that several nests were stacked within the same tooth socket.


The karst landscape of the region partly explains this unusual behavior. Natural soils there are scarce, often leached into caves where they accumulate. These deposits constitute one of the few substrates suitable for digger bees, thus encouraging them to venture into underground cavities to find nesting sites.

Published in Proceedings of the Royal Society B: Biological Sciences, this research documents a phenomenon with no known equivalent.