Some classes of animal are so successful that they spread into virtually every ecosystem, whereas others gradually recede until they inhabit only small niches in geographically isolated areas and thereby become threatened. Insects are definitely of the former sort and ants are the most successful of these, ranging from the Arctic Circle to Tierra del Fuego. Hence, no species of ant is a threatened species. The argument is flawed because it takes for granted that ['what is true of a whole is also true of its constituent elements', 'the Arctic Circle and Tierra del Fuego do not constitute geographically isolated areas', 'what is true of the constituent elements of a whole is also true of the whole', 'because ants do not inhabit only a small niche in a geographically isolated area, they are unlike most other insects']