HONG KONG — Ever wondered how many ants are crawling around on Earth? Scientists have tackled the seemingly impossible question and reveal a mind-boggling conclusion: There are 20,000,000,000,000,000 ants on the planet.
More simply put — that’s 20 quadrillion, or 20 followed by 15 zeroes.
The question has been addressed by a team from the Insect Biodiversity and Biogeography Laboratory of the School of Biological Sciences (SBS) at The University of Hong Kong (HKU). In their work, they also calculated the total biomass of all these ants, putting in perspective their prominence on our planet.
“The astounding ubiquity of ants has prompted many naturalists to contemplate their exact number on Earth, but systematic and empirically derived estimates are lacking. Integrating data from all continents and major biomes, we conservatively estimate 20 × 1015 (20 quadrillion) ants on Earth, with a total biomass of 12 megatons of dry carbon,” study authors write in their paper. “This exceeds the combined biomass of wild birds and mammals and equals 20% of human biomass.”
“While these questions may appear trivial at first, they have enormous implications for our understanding of natural processes since ants are such key players in most ecosystems and have numerous and complex interactions with other organisms.”
The study highlights not only the central role ants play in terrestrial ecosystems, but also major ecological and geographic gaps in our current knowledge. Scientists believe calculating how many ants there are on Earth and their biomass will help them understand the natural processes of Earth’s various ecosystems better.
“For decades, ant researchers have been incredibly busy studying ant communities the world over. They have collected thousands of ant samples to identify the species and often counted all the ants as well when publishing their results in scientific articles,” explains co-lead author Dr. Patrick Schultheiss, a postdoctoral fellow at SBS, during the study, in a statement.
“We were able to compile such data from nearly 500 different studies from all over the world and written in many different languages,” he adds. “In this way, we have been able to quantify the density of ants in various parts of the globe, and also to estimate the total number of ants on Earth.”
Ants discovery also points to biodiversity research issue
Researchers found that ants tend to be most prevalent in tropical regions of the planet. Co-lead author Dr. Sabine Nooten says the sheer number of the insects is “hard to grasp and appreciate.” Nooten recently left the research team in Hong Kong to study at Julius Maximilian University of Würzburg, Germany.
“Ants are particularly abundant in forests, and surprisingly, in arid regions but become less common in human-made habitats, with potential consequences for the ecological services (e.g. decomposition, pest control) they may provide,” she says.
One interesting takeaway for scientists is that the revelation also sheds light on just how little is known still about our planet.
“This is very worrisome as the world is changing rapidly, and scientists are lacking baseline information on how biodiversity may be changing in these regions,” says senior author Dr. Benoit Guénard, head of the Insect Biodiversity and Biogeography Laboratory of HKU SBS. “Societies and governments need to be more proactive about this and make important efforts and investments to fill these gaps. Counting ants is not a difficult exercise, and citizens from all over the world, with the right methodology, could be involved in providing a more profound understanding of the changes that are happening over time and space.”
The study is published in the Proceedings of the National Academy of Sciences.
South West News Service writer Dean Murray contributed to this report.