**If we put all the ants of the world on the scale at the same time, they would weigh as much as all the inhabitants of the Earth put together …** The statement, and the considerations that follow, are certainly not new and periodically "debate" on blogs and social networks. How much is true?

the origin. The statement first appears in a 1994 essay, Journey To The Ants, by biologists Edward Wilson and Bert Hoelldobler (University of Harvard, USA). The two were based on an assessment by the British entomologist CB William, who estimated the total number of terrestrial insects at a given time in **one million trillion**, which in the US / Anglo-Saxon notation equals 1 billion billion.

An inaccurate estimate. If the ants make up 1% of the global insect population (conservative value), then there are in total about 10 million billion. The two conclude that, since a single worker ant weighs from 1 to 5 mg (milligrams), the total weight of all the ants in the world reaches that of the entire human population. But in their calculations something does not come back.

The most famous "historical lies" on animalsToo heavy. Wilson and Hoelldobler started from the assumption that on average a human being weighs 1 million times more than an ant. But if we take an average weight of 62 kg per person, then an ant should weigh about 60 mg: there are some of this size, but these are really big ants. If we consider the 13 thousand species of ants present in the world, with lengths between 1 and 30 mm, the average weight reaches a maximum of 10 mg.

Where the scale falls. Even Wilson and Hoelldobler admitted the miscalculation. There are 7.2 billion people on the planet today: if we consider only all those over 15, our total weight reaches around 332 billion kg. Assuming there are 10 million billion ants on Earth, with an average weight of 4 mg, their total weight reaches 40 billion kg. Even if we raise the average weight of each one a little, the comparison remains unequal.

Then there is the question of the number of ants: nobody really knows him. Some say, indeed, 10 million billion, but there are also those who say just 100, 000 billion.

In any case, if the comparison does not hold up today - also due to the growing weight of the human population, which increasingly tends to obesity - it should have been worth 2, 000 years ago, when it was wider on Earth.