A fossil discovery on the Caribbean island of Hispaniola shows that solitary bees nested inside the empty tooth sockets of mammal bones left by owls in a cave around 20,000 years ago. The finding, published in 2025, marks the first known evidence of bees using animal bones for reproduction.
Researchers identified the nests while studying bones from a limestone cave in the Dominican Republic. Lead author Lazaro Viñola López of the Field Museum noticed smooth, concave deposits inside jawbone sockets that resembled mud chambers made by modern solitary bees.
CT scans confirmed the structures matched bee nests and preserved ancient pollen grains. The bees likely mixed dirt with saliva to build the tiny chambers, each smaller than a pencil eraser, possibly to protect eggs from predators.
The nests received the name Osnidum almontei, honoring paleontologist Juan Almonte Milan. No bee bodies survived in the warm cave conditions, leaving the exact species unknown.
Viñola López noted the limestone landscape offered few soil nesting sites, making the owl-deposited bones a rare opportunity for the insects.