When temperature and moisture conditions within the colony can be improved by creating above-ground living space, you will see the mounds pop up. The mound is an above-ground "nursery" that provides optimal temperature and moisture conditions. The workers move the brood and the queen(s) around the tunnels as needed to keep them in the best conditions. On sunny winter days the workers move the brood to the warmer, upper portions of the mound to take advantage of the extra heat. When it is too hot or too cold, fire ants will move deep into the ground to be protected from these weather extremes. Mounds frequently arise during times of moderating temperatures (spring, fall) or after a rain. The mounds that "pop up" are from colonies that have been living underground. Mounds may also appear because the ants are cleaning out tunnels or preparing for a nuptial flight of reproductive ants.

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