Bees could teach humans a thing or two about social distancing
Bees have all kinds of tricks to stop diseases getting into the hive. But if one gets infected, it's time to for its neighbours to drag it to its death
by Chris Baraniuk
If you want to observe a society excellently equipped for keeping disease at bay, forget – for a moment – about humans. Look instead to your nearest honeybee colony. For there you will find a rich array of sanitising strategies.
From social distancing to antiseptic treatments and even pseudo-vaccines, research suggests that bees have evolved multiple forms of “social immunity” that help them maintain healthy hives, says Alison McAfee, a honeybee researcher at North Carolina State University.
“They have this really neat strategy where they can actually share small bits of molecules that look like a virus among one another and that lends them immunity,” she explains. “It can be thought of as a vaccine.”
A study on this very phenomenon published last year revealed how bees pass on these molecules via the jellies they secrete in honeycomb for larvae to eat. And bees also coat parts of their hive in a sticky resin called propolis, long known to have antimicrobial properties. Because they apply it to the hive entrance, it’s a bit like when humans use hand sanitiser on arrival at a shop, suggests McAfee.
But if you think that bees might provide an inspirational model for humans when it comes to disease control, think again. Bees are ruthless. As soon as one member of the colony gets infected with a pathogen, the niceties are over. “They essentially murder the sick,” says McAfee.
This often takes the form of physically dragging the stricken bee out of the hive and tossing it to the ground, where it will perish. Studies have even found that bees sometimes remove themselves from the colony when they fall ill, a phenomenon termed “altruistic suicide”.
This, says McAfee, could be thought of as an extreme form of social distancing. But it seems extraordinarily unsympathetic to humans. The old cliché of “survival of the fittest” – sometimes used by heartless humans in an effort to justify compassionless behaviour – is at work here, at a colony level.
During the Covid-19 pandemic, many articles have been written that point out how common social distancing and isolation is among animals – apparently as a prompt for those who have been lax at donning masks or following distancing guidelines. Sometimes, however, these albeit fascinating write-ups have missed a crucial difference between people and animals.
It comes down to ethics, says McAfee. Luke Holman, a bioscientist at the University of Melbourne, is currently studying social immunity in honeybees and says that, for bees, the survival of the colony is paramount in a way that is quite alien to us. Bees preserve their genes through the survival of the colony so when they take merciless or “suicidal” actions, they are “saving themselves in a sense – just indirectly.”
“If you get sick, your presence is no longer useful to the hive,” says Holman.
And yet there are illuminating examples in social insects that reveal how they can also protect one another in the face of a pathogenic threat, notes Dana Hawley, professor of biological sciences at Virginia Tech.
She refers to a study by researchers in Austria and Switzerland, published in the journal Science in 2018, which found that ants have evolved social distancing practices in order to keep the spread of pathogenic fungus at bay in their nests. There was a significant degree of separation between forager ants – more likely to encounter the fungus outside and bring it back to the hive – and the queen or young workers nursing larvae.
“Simulations indicated that this organization disproportionately protects high-value individuals from the most likely source of disease,” the authors wrote.
For Hawley, this is reminiscent of the way in which healthcare workers during the Covid-19 pandemic have in some cases separated themselves from their families for months on end, in order to reduce the likelihood of passing on the virus. But again, animals don't provide an exact parallel. For humans, such severance is extremely unusual. “It’s quite the sacrifice that a lot of people have made,” says Hawley.
Plus, animals like ants rely on chemical signals to trigger social distancing. Scientists are still working out what these signals are and how they work but it’s notable that, for ants, the behaviour of an entire colony can change within hours of a pathogenic fungus entering the nest. Sick ants quickly self-isolate, for example. This may be possible thanks to chemical cues produced by the ants, though the details of this remain a mystery.
Other species have been shown to trigger social distancing behaviour via chemical signalling – including lobsters. Donald Behringer, professor in the school of forest resources and conservation at the University of Florida, and colleagues have demonstrated how lobsters can tell that one of their group is under the weather thanks to a chemical marker dispersed in the sick lobster’s urine. That individual is then kept at a distance.
Because the cue spreads into the surrounding water, lobsters don’t even need to catch sight of the infected crustacean to know they are nearby.
Behringer points out that there’s no real parallel to this in humans. We like to think that we can tell when to avoid someone for hygiene reasons by listening out for symptoms such as coughs and sneezes. But research has shown that we aren’t able to distinguish “healthy” coughs from infectious ones.
“Those auditory and visual cues of illness are not very efficient means of detecting disease,” says Behringer. “We’re usually not right that someone’s infected by using those kind of cues.”
Besides, for humans it might feel pretty harsh were all infected people biologically marked as such and ostracised by others. Though that’s not to say this sort of thing doesn’t happen in human society – just consider how disabled people feel about constantly being marginalised.
If the animal kingdom doesn’t provide a perfect template for how human beings should treat one another in times of contagion, it does at least hint at how measures like social distancing can be effective. Clearly, they have a long-standing evolutionary basis for some species. But we can actually go a bit further than that, especially when we look to animals that are genetically much closer to human beings than ants or bees.
A study published earlier this year, just as the Covid-19 pandemic was emerging, revealed how mandrill monkeys make important choices when distancing themselves from individuals that have become sick. Mandrills are able to tell when a member of their group is ill by smelling their faeces, which means they can then keep those individuals at a distance. But the new research showed how mandrills continue to groom and remain physically close to their immediate family members even when they catch the infection. “Those family bonds are so important that they continue to engage in them,” says Hawley.
In humans and closely related species, social ties have been shown to be good for survival. And when it comes to a pandemic situation, we have clearly developed a special approach to tackling disease. We are not like bees, whose whole – short – lives are tied to the survival of the colony. We are a far more individualistic species. Our societies have evolved to preserve people’s lives, sometimes at very high cost, rather than sacrifice them as a matter of course. Despite the fact that there is, sadly, a long list of incidents throughout history and the present when this ethical principle has been disregarded.
Ultimately, the pandemic has forced us to take a community-minded approach, says Hawley: “one characteristic of infectious diseases like Covid that’s critical is that your own health depends on how everyone else behaves.” Somewhat paradoxically, this is the best way for all of us, as individuals, to survive, she says.
A community collaborating in order to protect individuals is a very human response. There are semblances of such behaviour in some other species. But this, though we don’t always get it right, is our evolutionary specialty.
More great stories from WIRED
🐾 A liver disease is putting the Skye Terrier’s existence at risk. Doggy DNA banks could help save it
🔞 As AI technology gets cheaper and easier to use, deepfake porn is going mainstream
🏡 Back at work? So are burglars. Here’s the tech you need to keep your home safe
🔊 Listen to The WIRED Podcast, the week in science, technology and culture, delivered every Friday