HomeScience20 trillion ants are currently roaming the earth, scientists calculate
20 trillion ants are currently roaming the earth, scientists calculate
September 19, 2022
When Mark Wong began analyzing 489 entomological studies spanning every continent, major habitat and biome on Earth, he had a simple goal: to count the ants. The journey to a definitive answer was long and often tedious. Then, one day, Wong and fellow ant experts came out on the other side.
According to a new paper published Monday in the journal PNAS, the international team of scientists suggests that there are currently as many as 20 quadrillion ants roaming our planet. That’s 20,000,000,000,000,000 of those six-legged worker insects you catch by pollinating plants, spreading seeds like little gardeners, and salivating after a toasted bagel.
“We further estimate that the world’s ants together make up about 12 megatons of dry carbon,” said Wong, an ecologist at the University of Western Australia’s School of Biological Sciences. “Impressive, this exceeds the biomass of all the world’s wild birds and mammals combined.”
To put that staggering amount into perspective, multiply the team’s ant biomass estimate by five. The amount you get is equivalent to just about the entire human biomass on Earth — and this could be a… conservative estimation. Each of the 489 global surveys was quite thorough — tens of hundreds of booby-trap tactics were used, such as trapping runaway ants in small plastic container ditches and gently shaking leaves to learn how many are hiding in crusty homes. But as with most research efforts, caveats remained.
For example, the sampling sites, Wong explains, were unevenly distributed across geographic regions, and the vast majority were collected from the soil layer. “We have very little information about ant numbers in trees or underground,” he said. “This means that our findings are somewhat incomplete.”
Why worry about counting ants?
Despite their small size, ants carry quite a bit of power.
Aside from tunneling seeds into the ground for dinner and accidentally blooming plants from their leftovers, these buggers are integral to maintaining the delicate balance of our ecosystem. They prey on larger animals, predators of many others, bottom carp and scavengers, just to name a few of their accolades. So given the sheer amount that adorns the earth, they are quite important. “This sheer mass of ants on Earth strongly underscores their ecological value, as ants can exceed their weight in providing important ecological functions,” Wong said.
But when it comes to to count ants specifically, as Wong did, there is an urgency that comes from the rate at which our climate is changing. Scientists need to quantify how many ants, as well as other animals and insects, exist on Earth, as the climate crisis — a threat exacerbated by human activity — is forcing global temperatures to rise, threatening these organisms with extinction.
“We need people to rigorously and repeatedly examine and describe the ecological communities of different habitats before they are lost,” Wong said, stressing that the team’s recent work provides an important foundation for ant populations, so we know how the communities of these insects might change in conjunction with a warming climate.
A worst-case scenario where our fellow Earthlings aren’t counted is sometimes called “dark extinction” or anonymous extinction. It’s just the concern that many species are going under the radar as the climate crisis worsens due to things like habitat loss or habitability.
Those animals headed for extinction may not even have been documented, let alone studied in detail.
In this regard, the team’s PNAS study opens with a poignant quote from American biologist and ant specialist Edward O. Wilson: “Ants make up two-thirds of the biomass of all insects. There are millions of species of organisms and we know almost nothing about them. “
In the future, this is why Wong believes it is important to regularly survey ant populations and even speed up the process by outsourcing it to anyone who can and will participate. “Things like counting ants,” he said, “taking pictures of the insects they encounter in their backyards and observations of interesting things plants and animals do can go a long way.
“It would be great – as the eminent ant biologist EO Wilson once suggested – just to have ‘more boots on the ground’.”