I don’t know how many in the world, but this summer there must be at least ten million of them on my 44 acres, despite the many times I’ve sprayed insecticide on their mounds within 50 yards of my house..
Some of them have gotten smart too. Several of the newer colonies of the tiny black ants quit building mounds and tunnel under clumps of grass, spreading the excavated dirt afar, so it is more difficult to find them.
Ever try Termidor SC (Fipronil)? Twice a year and the little buggers are gone!