The phenomenon that human society resembles a small-world network with short path lengths, i.e. any two human beings tend to be linked through a small chain of friends of friends.

Alternative form of have the world by the tail

Alternative form of have the world by the tail

Alternative form of have the world by the tail

Alternative form of have the world by the tail

Alternative form of have the world by the tail

Alternative form of have the world by the tail

plural of Old World porcupine

plural of New World porcupine

Any of the large, arboreal, spiny-furred rodents of the family Erethizontidae, native to forests and wooded regions of North America and northern South America.