Undertaker Bees are middle-aged honey bees that serve to search the hive and beyond for their dead. They can find them in the dark with great accuracy and in as little as 30 minutes. This is unique because the dead have not decomposed to the early stages yet which give off the typical odors of decay. A new study may reveal how they do it. “The task of undertaking is fascinating” and the new work is “pretty cool,” says Jenny Jandt, a behavioral ecologist at the University of Otago, Dunedin, who was not involved with the study.
Wen Ping, an ecologist at the Chinese Academy of Sciences’s Xishuangbanna Tropical Botanical Garden, wondered whether a specific type of scent molecule might help undertaker bees find their fallen hive mates. Ants, bees, and other insects are covered in compounds called cuticular hydrocarbons (CHCs), which compose part of the waxy coating on their cuticles (the shiny parts of their exoskeletons) and help prevent them from drying out. While the insects are alive, these molecules are continually released into the air and are used to recognize fellow hive members.
To ensure the accuracy of the findings, Wen washed the CHCs with hexane off dead bees, which can dissolve waxes and oils, heat them up to around a live bee’s temperature, and bring them back in their respective hives.
The ability to recognize death is not an easy process. Yehuda Ben-Shahar, an entomologist at Washington University in St. Louis, says more research will be needed to shore up Wen’s claims. “I think this study is a good start,” he says. “It does make sense that there is some chemical signature of a dead bee, but I wouldn’t say that we now know exactly what is going on.” For example, although bees can “smell” with their antennae, they can also “taste” with their feet, he notes, which might add another layer to the way they perceive dead comrades.