Scientists estimate that there are more than 20,000 species of ants. The species range in size from 1 mm long to 38 mm long and live in most environments. The diets of ants range from flowers and seeds to fluids from their own larvae. Ants have been able to successfully inhabit so many different environments because their populations have been able to — occupy habitats that have no other life-forms
occupy habitats that have no other life-forms

fill niches usually occupied by mammals
fill niches usually occupied by mammals

adapt to a variety of habitats and food sources
adapt to a variety of habitats and food sources

hybridize with other species of insects