Researchers compiled hundreds of studies of tree-dwelling and ground-dwelling ants to make their estimate that for every human on Earth, there are 2.5 million ants.
In this photo provided by the U.S. Fish and Wildlife Service, yellow crazy ants are seen in a bait testing efficacy trial at the Johnston Atoll National Wildlife Refuge in December, 2015. An invasive species known as the yellow crazy ant has been eradicated from the remote U.S. atoll in the Pacific.In this photo provided by the U.S. Fish and Wildlife Service, yellow crazy ants are seen in a bait testing efficacy trial at the Johnston Atoll National Wildlife Refuge in December, 2015.
The scientists analyzed 489 studies across all continents, biomes and habitats that used methods such as studying leaf litter, which help study tree-dwelling ants, and setting pitfall traps, which is done by placing a beaker into the ground so that the top is level with the surface, causing ground-dwelling ants to fall in.
There are 15,700 known ant species and subspecies. These six-legged creatures serve vital roles in the ecosystem, as they help spread plant seeds, accelerate decomposition and support the food chain as both predator and prey. Despite their grand numbers, though, their populations are declining due to habitat destruction, invasive species and climate change.