Fire Ants in the Fall

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The other day I went outside to get the paper and I noticed a fire ant mound on the edge of the driveway.   Its fall… the temperature has dropped… why all of a sudden do I have fire ants?  Then I looked around the yard and found five more mounds.  What is going on here?!  September was a really wet month and we received above average rainfall.  It seems like the ants just appear after a good soaking rain, but they were already there living underground.  The colonies are not as visible during dry weather because they try to stay close to the water table.  After a good rain the water table rises and they begin building up their mounds and become more visible.  I grabbed some fire ant bait and sprinkled some around the mounds.  That should take care of them!

The next day I checked the mounds but, alas, the fire ants were still alive.  The bait that I applied was gone, but the ants didn’t seem to be affected.  What gives?  My neighbor saw me staring at the ant mounds and he strolled over.  “Oh, I see you have fire ants too” he says.

“Yeah, I put some bait out but it didn’t work.”

“Well, I just poured some gasoline on the mounds in my yard and that took care of’em.”

I glanced over at his yard and saw the dead patches of grass where the ant mounds previously were.  I noticed smaller mounds that were beginning to appear near the dead spots.

“Yep, you sure showed them.  But, gas is so expensive these days and I can’t afford to waste it on fire ants.  Not to mention the cost of sod to replace the dead grass.  Plus, you’ve got more mounds popping up in other places.  That means more gas and more dead grass.  Next time, talk to me first and I’ll tell you about the Terminix fire ant control program.”

He glanced down at the ant mound in front of us and said, “It doesn’t look like your control program works.”  I guess I’ve got some explaining to do.

Fire ants have become the bane of the southeast.  Since they were accidentally introduced into the U.S., they’ve spread like… well, wildfire.  Every place they have invaded they have been economically and ecologically devastating.  There has been tons of research conducted to find ways to control them, but it’s been difficult.  Some of these ways include introducing their natural enemies such as decapitating phorid flies, nematodes, viruses, and parasitic ants.  These have reduced their numbers in some areas but they do not eliminate them.  In the mean time, frustrated homeowners have attempted their own control tactics which usually involves using caustic materials such as gasoline, kerosene, boiling water, bleach and other cleaners.  All of these are dangerous to use and will kill ants that contact them, along with your grass and other nearby plants.  The next day you kick open the mound and see a bunch of dead ants and you assume that you killed them all, but you may not have gotten to the queen and workers that were deep underground and quickly moved to another location when they realized something was amiss.  By the way, grits or soda water does not work either.  I really don’t understand why grits became such a widespread phenomenon of trying to control fire ants.  I’m going to go off on a tangent here and explain why this is ridiculous.  First of all, the adult fire ants cannot ingest solid food.  When instant grits are scattered around the mound, the adult ants will take the flakes down into the colony and give them to the larvae.  The larva chews up the grit and turns it into a paste that the adult ant can now eat.  It doesn’t swell in their stomachs and cause them to explode.  All you have done is fed the ants.  OK, let me get back on track.  Many chemicals were also studied for their effectiveness in killing fire ants and the colony can be eliminated by drenching the mound with certain insecticides.  The drawback is that you only eliminate that one colony and there can be several colonies in the area that are not visible because they haven’t built up their mounds.   What research has found is that the best way to eliminate fire ants from an area (like your yard) is by spreading an attractive bait product over the entire yard.  It will even eliminate the unseen colonies.  This is the method used by Terminix Service for our fire ant control program.

So why didn’t my bait work the other day?  Well, when the temperature changes in the fall the ants change their behavior and food preferences.  Bait that was highly effective in the spring and summer may not work during the fall.   During this time of year we will switch to a granular insecticide to knock down fire ant colonies and they will stay down during the winter months.  Then in the spring, when activity begins to increase, we will apply the bait product and do a second application during the summer.   It is a highly effective program that keeps fire ants away.

I think I convinced my neighbor to give this a try for next year and I told him if it doesn’t work he can go back to killing his grass.  I then went and grabbed the granular insecticide that I should have used in the first place.