Fire ants use trees as a nesting place because there is little or no soil disturbance.
Moisture and food resources are plentiful on and around trees and shrubs.
Ants in mounds at the base of trees are probably not causing any damage to well established trees.
They may actually help by preying on other insects that feed on parts of the tree and may reduce compaction by tunneling in the soil.
However, very young, tender trees can be damaged by the ants girdling the plants and allowing roots to be exposed to the air, thus drying out root systems.
This has been observed, for example, in crepe myrtles and newly planted citrus trees, so fire ant control methods will need to be used in such areas.
Related
Fire Ant Habitat and Food Sources
Find more information about fire ants in eXtension's Imported Fire Ant Resource Area.
