It rains on Tuesday, and by Wednesday morning the yard is covered in fresh fire ant mounds. If that sounds familiar, you are not imagining it. Rain is one of the biggest triggers for new fire ant mounds in Central Texas.
Why Mounds Appear After Rain
Fire ants live mostly underground. When heavy rain soaks the soil and floods their tunnels, the colony moves up and rebuilds the mound above the waterline. That fluffy pile of fresh dirt is the colony relocating its brood and queens to drier ground. In severe flooding, fire ants can even link together into floating rafts.
In other words, the ants were already there. The rain just made them visible.
Why Treating One Mound at a Time Fails
Most Texas fire ant colonies have more than one queen, and a single yard can hold many connected colonies. When you pour or sprinkle something on a mound, you usually kill part of that colony. The survivors move a few feet away and build a new mound, which is why the problem seems to spread every time you treat it.
What Works: Treat the Whole Yard
Texas A&M AgriLife recommends a two-step approach for yards with frequent fire ant problems:
- Broadcast a fire ant bait across the whole yard. Foraging ants carry the bait back to the queens, reaching colonies you cannot see.
- Treat individual mounds that are in high-traffic areas or need faster results.
Baits work best when ants are actively foraging, the grass is dry, and no rain is expected for a day or two. Using fresh bait matters too, since old bait loses its appeal.
What Eats Fire Ants in Texas?
Fire ants have some natural enemies, including native ants that compete with them and tiny phorid flies that were introduced in Texas to attack fire ants. Birds, armadillos, and other animals eat some as well. None of them keep a yard free of mounds, so treatment is still needed where people and pets spend time.
Fire Ant Safety
- Keep kids and pets away from mounds, especially right after rain
- If stung, wash the area and use a cold compress, and do not pop the white pustules that form
- Call 911 for trouble breathing, swelling of the face or throat, or dizziness
Learn how to identify fire ants and their mounds on our fire ant page, see how we treat yards on our fire ant treatment page, or compare all Central Texas ants on our ant control page.
Mounds taking over the yard? Call 830-777-CAMO (2266) for yard-wide fire ant treatment in New Braunfels and the surrounding area.
