How many ants are there on Earth? When we were children we often asked such riddles and answered with ridiculous numbers. But today we have a scientific answer. According to a recent study published in the journal Science, there are 20,000,000,000,000,000 (20 thousand million million or 20 quadrillions) individual ants on earth. They weigh more than the combined biomass of all wild birds and mammals and are equal to 20% of all human beings weighed together. Ants are ubiquitous and part of our day-to-day life – they create a nuisance by encroaching on every nook and corner of our homes, raiding food, and occasionally delivering irritating bites or painful stings. But, how much do we really know about ants? Why are they always seen marching together like a disciplined army regiment? Where do they live and what do they eat? ‘Familiarity breeds contempt’ is true about ants too. We ignore them and hate them because of the little nuisances they cause and forget the great services they provide to nature, making our life comfortable on Earth.