When Mark Wong set out to analyze 489 entomological studies spanning every continent, major habitat and biome on Earth, his goal was simple: count ants. The journey to a final answer was long and often tedious. Then one day, Wong and other ant experts came out the other side.
According to a new paper published Monday in the journal PNAS, the international team of scientists suggests that there are currently 20 quadrillion ants roaming our planet. That’s 20,000,000,000,000,000 of those six-legged worker bugs you catch pollinating plants, scattering seeds like little gardeners, and salivating over a toasted bagel.
“We further estimate that the world’s ants collectively constitute about 12 megatonnes of dry carbon,” said Wong, an ecologist at the University of Western Australia’s School of Biological Sciences. “Impressively, this exceeds the biomass of all of the world’s wild birds and mammals combined.”
To put this staggering amount into perspective, multiply the team’s ant biomass estimate by five. The number you get is roughly equivalent to all of the human biomass on Earth – and that could be a conservative estimate. Each of the 489 global surveys was quite thorough – employing tens of hundreds of trapping tactics like catching fleeing ants in small plastic ditches and gently shaking leaves to find out how many are taking refuge in crusty houses. But as with most research efforts, caveats remained.
Sampling locations, Wong says, were unevenly distributed across geographic regions, for example, and the vast majority were collected from the soil layer. “We have very little information on the number of ants in trees or underground,” he said. “This means that our conclusions are somewhat incomplete.”
Why bother counting ants?
Despite their small size, ants are quite powerful.
Besides digging seeds in the ground for dinner and accidentally making plants bloom from their remains, these buggers are integral to maintaining the delicate balance of our ecosystem. They are the prey of larger animals, the predators of many others, the churners and scavengers of the ground, to name just a few of their distinctions. So, considering the huge number of them that adorn the Earth, they are quite significant. “This huge mass of ants on Earth strongly underscores their ecological value, as ants can punch above their weight by providing key ecological functions,” Wong said.
But when it comes to account Specifically, as Wong did, there is an urgency stemming from the rate at which our climate is changing. Scientists need to quantify how many ants, along with other animals and insects, exist on Earth, as the climate crisis – a threat exacerbated by human activity – is forcing global temperatures to rise and therefore putting these organisms at risk of extinction.
“We need people to rigorously and repeatedly study and describe the ecological communities of different habitats before they are lost,” Wong said, noting that the team’s recent work provides an important baseline for ant populations, so we know how these insect communities might change. along with global warming.
The worst-case scenario of not counting our earthly friends is sometimes called “dark extinction” or nameless extinction. It’s simply the fear that many species could disappear under the radar as the climate crisis deepens due to things like habitat loss or uninhabitability.
These endangered animals might not even be documented, let alone studied in detail.
In this regard, the team’s PNAS study opens with an apt quote from American biologist and ant scientist Edward O. Wilson: “Ants make up two-thirds of the biomass of all insects. There are millions species of organisms and we know next to nothing about them.”
Going forward, that’s why Wong thinks it’s important to survey ant populations regularly, and even speed up the process by contracting it out to anyone able and willing to participate. “Things like counting ants,” he said, “taking pictures of insects they encounter in their garden and noting observations of interesting things plants and animals do can go a long way.
“It would be great to have – as the eminent ant biologist EO Wilson once proposed – simply ‘more boots in the field’.”