In the case of contact insecticides used as individual mound treatments it is best not to disturb fire ant mounds prior to application, because disturbing a fire ant mound often causes the colony to relocate. Thus, you may not be able to kill many ants before they evacuate into subterranean tunnels.
However, if you are applying a fire ant bait, the mound may be disturbed without reducing the effectiveness of the baits. Recent research has shown that ants from disturbed mounds still pick up bait effectively and distribute it throughout the colony, resulting in good control. Be warned that disturbing a mound may expose you to the wrath of the fire ant colony. Always use caution when you are around a fire ant colony, in order to avoid being stung.
See also FAQ #1116: "Why do imported fire ant colonies move when I treat the mound with a pesticide?"

