Bees Can Live Underwater, And ‘Gills’ May Be Involved

If you want to attract bees to your garden, a special, shallow “bath”, which isn’t deep enough for our flying friends to fall into, is a great place to start.

But for queen bumblebees, apparently, a mini plunge pool would pose no threat.

That’s because new research published in the Royal Society’s Proceedings B has found that bumblebee queens can “avoid drowning” through “underwater respiration,” allowing them to live underwater for days.

A 2024 paper showed that bumblebee queens can live underwater for anywhere from eight hours to seven days. This newer research sought to figure out how.

Some bee species, including bumblebees, enter a period of deep rest called “diapause” in the winter. In that time, their metabolism and development slow way down.

But sometimes, the world around them doesn’t stay as rested. Flooding, for instance, can affect a hive (many of which stay underground in the colder months).

Scientists figured the response to submersion noted in the 2024 research was a survival tactic from the bumblebee queen. So, for this study, they put some bumblebee queens who were in diapause underwater and measured the gaseous exchange.

They found that carbon dioxide levels rose, while oxygen levels sank, suggesting the bees were respirating.

But the carbon dioxide emissions decreased compared to those emitted when the bees in diapause were out of water.

Researchers linked this to metabolic activity; the less that was happening in bees’ bodies, they reasoned, the lower the CO2 output would be.

Prior to being placed underwater, diapausal queen bees – whose metabolism had already dropped compared to non-diapausal levels – produced 15.42 microlitres of carbon dioxide per hour per gram of body mass.

But after eight days underwater, that shrunk to 2.35 microlitres. That’s almost a six-fold decrease in presumed energy use.

Scientists termed this a “profound metabolic depression”.

That dip in metabolic activity explained some of the survival rates of queen bees living underwater. But, quick question – how are they getting enough oxygen to respirate in the first place?

Well, scientists couldn’t answer that definitively in this study. However, they hypothesised that queen bees can form a kind of “physical gill” with trapped air that allows gas exchange.

“Future studies manipulating water conditions and the likely physical gill, alongside detailed recovery analyses, will further clarify the adaptations enabling queens to withstand extended submersion,” the researchers wrote.