The strange case of a bee‘s nest discovered inside bone fossils on the Caribbean island of Hispaniola is a first-of-its-kind discovery that highlights nature’s creativity.
Thousands of years ago, giant barn owls made a meal of a large rodent called a hutia, whose jaw, devoid of its teeth, would one day be the basis of a bee’s nest. Over an extended period, other bees from the swarm continued to nest in the fossils, as reported in a recent paper published in the journal Proceedings of the Royal Society B: Biological Sciences.
Cave Fossil Discovery
“Usually, when collecting fossils, you get all the sediment out of the alveoli while cleaning the specimen,” said Lázaro W. Viñola-López, lead author on the new study, who initially worked on the fossil excavation while still a doctoral student.
Fortunately for this discovery, Viñola-López was not so quick to clean and tag the fossil for storage without a thorough examination. Despite the scarcity of hutia fossils across the island, a large number were found in a single cave, which sparked his interest. While examining the extensive fossil collection, he noted an unusually smooth tooth socket—unlike the typically rough texture of bone.
“I’d seen something similar in Montana when I was collecting dinosaur fossils in 2014,” he said, referencing a previous discovery of wasp cocoons alongside bones. “It would be nice to write a short paper reporting the occurrence of these wasp nests in the mandibles,” he continued, explaining his decision to pursue the odd fossil.
An Unexpected Discovery
When Viñola-López first proposed the idea to his colleague and co-author on the new paper, Mitchell Riegler, Riegler was unenthusiastic. Years later, however, while searching for a quick project to turn into a paper, Riegler revisited the idea.
“I told Lazaro we could do it only because I thought it’d be fast,” Rigler said. “We’d scan them, describe their shape, and say that they were there. Boy, was I wrong.”
That early assumption changed when the pair discovered an ichnofossil study describing wasp nests that differed markedly from those they had found on Hispaniola. Typically, wasp nests are rough-textured, composed solely of saliva and a mixture of dirt or plant fiber. What they found in the jawbone nests was smooth, resembling bee nests, and coated in a waxy, waterproofing substance secreted by a special gland. At that point, the researchers realized that they had been looking at the wrong insect.
In the scientific literature, there had never been a documented case of a bee nest formed within an unaltered, preexisting fossil. The only comparable case involved burrowing bees that had drilled into human bones in a Roman necropolis—but those insects had modified the bone, unlike the unaltered fossils in this instance.
Following the Bees
Years of entomological research followed, as paleontologists consulted with modern bee experts to bridge the two fields. At one point, Viñola-López even returned to the original cave to study its stratigraphy. Eventually, the team was forced to quickly retrieve as many fossils as possible after a local resident’s failed attempt to convert the cave into a septic tank, raising concerns that the specimens were at risk.
“We had to go on a rescue mission and get as many fossils out as possible, and we got a lot of them,” Viñola Lopez said.
After a thorough examination of the cave’s history and stratigraphy, the researchers identified two additional fossil types that also contained bee nests. Other notable nesting sites included a hutia vertebra and the pulp cavity of a sloth tooth. Close examination revealed that the bees reused the same cavities to build new nests atop old ones—sometimes up to half a dozen times.
The researchers have developed a hypothesis explaining why the bees adopted the unusual practice of building nests not only inside fossils but also within caves, rather than in the open spaces where bees more typically dwell. They believe soil loss in the surrounding areas drove the bees into the cave, where they made use of its soft silt floor for burrowing.
“The area we were collecting in is karst, so it’s made of sharp, edgy limestone, and it’s lost all of its natural soils,” Riegler said. “I actually fell on it at one point, so I can tell you all about it.”
Research on the cave has not yet concluded, and the study’s authors are preparing follow-up work exploring additional unusual fossils from the site. That research is expected to illuminate further how species adapt to local conditions in strange and surprising ways.
The paper, “Trace Fossils within Mammal Remains Reveal Novel Bee Nesting Behaviour,” appeared in Proceedings of the Royal Society B Biological Sciences on December 17, 2025.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.