Ants have the particularity of being omnipresent on our planet. But how many are there exactly? And how can we count them? A study answers.

There are questions that we have never asked ourselves, but of which we are delighted to have the answer. How many ants are there on Earth? To answer this, four biologists published, on September 19, 2022, a amazing study : “ *The abundance, biomass and distribution of ants on Earth*.”

The question is less strange than it seems. As the authors write, *the astonishing ubiquity of ants has prompted many naturalists to wonder about their exact number on Earth *“. To find the answer, they integrated a large mass of data into their calculations. These come from all the continents and from the main biomes (sets of ecosystems characteristic of a biogeographical area).

## There are 15 zeros to the number of ants on Earth

Here is the exact figure: 20,000,000,000,000,000. You are not dreaming, there are 15 zeros. In words, this figure is expressed in billiards (quadrillion in English), that is to say a total of twenty million billion.

Since there are 8 billion human beings on Earth, the Washington Post recalls that means that for every human being, there are 2.5 million ants!

” *This figure exceeds the combined biomass of wild birds and mammals and is equivalent to 20% of human biomass *“, explain the biologists, in their paper. A recent study also counted the potential number of birds on the planet and arrived at the figure – huge, but less than that of ants – of 50 billion individuals.

The authors note that the abundance of ants is unevenly distributed on the planet, with a strong preponderance in the tropics.

## How to count ants?

We can imagine that the authors were not counting the number of ants by hand. But then how did they do it? They explain their method in a published post in *The Conversation*.

This is a meta-analysis of 489 studies done on ant populations around the world. These previous studies have each studied different very specific geographical areas with research in the field and in various ecosystems – forests, deserts, grasslands and cities. By mobilizing standardized methods, they each assessed the probable number of ants in the observed area.

The authors therefore used a method called *bottom up* (from bottom to top): they made calculations based on field data. Previous work used a top-down method instead, which involved applying counting theory models to estimate populations. As a result, this new study results in a much higher estimate than any before. And again: the authors consider that the figure is probably underestimated compared to reality.