There are about 20 quadrillion ants on the Earth at any given time, a new study has estimated. That’s 20,000 trillion individuals.
The estimate is two to 20 times higher than previous ones, according to the study, published in the journal Proceedings of the National Academy of Sciences on Monday.
“We were very surprised about the large number of ants we found,” Sabine S. Nooten, an insect ecologist and temporary principal investigator at the University of Würzburg in Germany, told CNN Tuesday. Nooten was a co-lead author of the study.
“We virtually didn’t have any expectations because the numbers which floated around beforehand in scientific literatures were basically educated guesses, and they had very little empirical data to work from,” she added. “And, so, this is the novelty of our study because we synthesized the data from a lot of empirical studies.”
The previous global estimate of between 1 quadrillion and 10 quadrillion ants by renowned biologists Bert Hölldobler and Edward O. Wilson assumed that they made up approximately 1% of the world’s estimated insect population of 1 quintillion individuals, according to the study.
However, the research team of this latest study based the new estimate on observational evidence from an extensive data set of globally distributed ant samples. The authors identified and assessed 465 suitable studies, encompassing 1,306 sampling locations, covering all continents and major biomes where ants live.
Scientists could use the study’s comprehensive data set, which spans 80 years, to predict what future communities or environments might look like, according to Nooten. For example, the team estimated the number of ground-dwelling ants, which densely populate tropical and subtropical regions, such as South American forests, to be around 3 quadrillion.