A billion ants live in New York City

These are, needless to say, big numbers. We have made a bunch of assumptions with this simple math, but the one most likely to be wrong seems to be the assumption that there are no ants in the places that are not green. Ants sometimes make it into apartments in New York (though the ants of New York City apartments have never been studied). At least three ant species, the cornfield ant (Lasius neoniger), the pavement ant (Tetramorium species E) and Monomorium minimum can nest under cement. Just how many of these ants are under cement is something you can guess at as well as I can, but whatever the number it would increase our estimate of the number of ants in New York by at least a billion and maybe much more. Nor do we consider the species that nest up in trees, species such as Camponotus pennsylvannicus. We have also not included baby ants, eggs, larvae and cocoons. Including their numbers would probably about double the number of ants in the city overall. Amazingly, because the estimates in Table 1 are so high it means that even some of the very rare ants in New York City, species that no one has ever studied and that we know essentially nothing about, may be more common than human New Yorkers.

More details at Your Wild Life, via Scientific American.