The result is staggering: 20 quadrillion – or 20,000,000,000,000,000 – ants roam the Earth, meaning that for each human being, there are about 2.5 million ants.
According to the experts, if all the ants were plucked from the ground and weighted, they would outweigh all the mammals and wild birds put together.
“I was amazed that the ants’ biomass was higher than that of wild mammals and birds combined, and that it reaches 20 percent of the human biomass. That gives you an understanding of the scale of their impact,” said study co-lead author Sabine Nooten, an insect ecologist at HKU.
“It’s unimaginable,” added study lead author Patrick Schultheiss, a researcher at the University of Würzburg in Germany. “We simply cannot imagine 20 quadrillion ants in one pile, for example. It just doesn’t work.”
Like humans, ants have spread almost all over the Earth. Although they are most abundant in tropical and subtropical regions, they can be found nearly everywhere besides the coldest parts of our planet. These insects play important roles in the proper functioning of a variety of ecosystems.
For instance, they aerate the soil and drag seeds underground to sprout, they serve as food for a variety of birds, mammals, and arthropods, and they help decomposing dead wood and other types of matter.
“Some ants can certainly be very annoying, but that’s a very human-centered perspective,” Schultheiss explained.
“Most ants are actually highly beneficial, even to us humans. Think about the amount of organic matter that 20 quadrillion ants transport, remove, recycle, and eat. In fact, ants are so essential for the smooth working of biological processes that they can be seen as ecosystem engineers. The late ant scientist E.O. Wilson once called them ’the little things that run the world.’”
While scientists are already seeing troubling declines in insect populations all over the world – caused by habitat destruction, climate change, and increased use of pesticides – they are not yet sure whether ants’ numbers are falling down too.
“We did not yet attempt to show this temporal shift in ant abundance. That would be something that would come next,” Nooten concluded.
The study is published in the journal Proceedings of the National Academy of Sciences.