Fire Ants On The March


    FIRE ANTS. The name alone is enough to make you cringe and remember the last time you accidentally stepped in an ant bed and were left fighting the urge to scratch the bites they left behind for days. There is no doubt they are pests to humans and animals-but they are also pests to our electric utilities.

    Since being introduced in the 1930’s by way of a Brazilian cargo ship docked at an Alabama port, fire ants have gradually made their way across the South.

In Texas, fire ants cause more than $146 million per year in damages to electrical and communications equipment. This type of damage makes fire ants a costly nuisance for electric providers across the state.

    Sam Houston Electric Cooperative incorporates fire ant control into the on-going maintenance program. Yet, despite these efforts, fire ants are impossible to completely eradicate and still make a nuisance of themselves across the Cooperative’s territory.

    “You can open just about any of our pad mounted transformers and find fire ants in them,” Larry Horn, Sam Houston EC Livingston operations supervisor, said.

    There are many different theories as to why fire ants have such a strong attraction to electrical equipment. Some studies have shown that ants stop in the presence of electrical fields surrounding wires and relay switches, which could be because of an attraction to vibrations emitted from the electric utilities.

     Others studies revealed that when ants are shocked by an open switching mechanism, they wave their abdomen and release pheromones, a communication chemical that attracts other ants; eventually, so many dead ants accumulate around the mechanism that it malfunctions.

Their attraction to electrical equipment could also be the simple reasons that pad mounted transformers are warm in the winter, cool in the summer and rarely disturbed-making an ideal nesting site.

Despite the reason behind their attraction, fire ants can cause major damage when they begin to take residence in electrical equipment. Most commonly, damage is caused to the metal cabinets surrounding transformers.

“When they build beds in a transformer, the soil causes moisture to build up, which eventually causes the cabinets to rust and deteriorate,” Horn said.

At times, ants can remove so much soil from underneath a transformer’s concrete slab that it begins to tilt, causing damage and oil leakage from the equipment.

In the worst case scenario, ants will remove enough soil from beneath the slab that transformers actually cave in. Ants can also chew through the wire coatings, causing short circuits.

Luckily, this maintenance program has so far prevented damage bad enough to cause major power outage.

“It’s a constant battle.” Horn said. “The situation has grown over the years and is showing no sign of slowing down.”