Ants are eusocial insects of the family Formicidae and, along with the related families of wasps and bees, belong to the order Hymenoptera. They are a diverse group of more than 12,000 species, with a higher diversity in the tropics. They are known for their highly organised colonies and nests, which sometimes consist of millions of individuals. Individuals are divided into sub-fertile, and more commonly sterile, females ("workers"), fertile males ("drones"), and fertile females ("queens"). Colonies can occupy and use a wide area of land to support themselves. Ant colonies are sometimes described as superorganisms because the colony appears to operate as a unified entity.