• those with only one queen (called monogyne)
  and
• those containing more than one fertile queen (polygyne)

Workers from monogyne colonies are territorial and defend the area around their mound from other fire ant colonies, new queens that land and attempt to start new colonies nearby or from other types of ant. Between 20-300 monogyne mounds have been found per hectare.

Ants from polygyne fire ant colonies are able to move from one mound to another without hostile reaction from other fire ant workers. This type of colony is more stable and can have between 680 and 2600 mounds per hectare.