They’re hairy. They’re crazy. They’re hairy crazy ants.

November 11, 2011


People who heard in mid-October about the spread of aliens on the Gulf Coast might have written it off as some kind of pre-Halloween spoof. Millions and millions of shaggy creatures running around at break-neck speed and with a penchant for overrunning and damaging homes and businesses sounded unbelievable.

But, when it comes to hairy crazy ants, fact is stranger – and more disturbing – than fiction.

“If you go to an area infested with these pests and take one step, in two seconds your feet will be covered in ants,” said Joe MacGown, research technician and scientific illustrator at Mississippi State University’s Mississippi Agricultural and Forestry Experiment Station. Pointing out that the ants have no natural enemies, he added, “We’re currently working on pesticides, but right now we don’t have anything that has proven very effective.”

The ant’s scientific name is Nylanderia pubens, but they are known by various common names. Researchers here in Mississippi prefer hairy crazy ants, a dead-on description of the introduced pests that have a shaggy appearance and move about frenziedly.

Thought to have originated in South America, hairy crazy ants were first discovered back in the 1950s in Florida. Approximately 40 years later, the Sunshine State labeled the pests as a serious threat.

In 2009, the tiny, burnt orange-colored ants were identified for the first time in Mississippi in two areas in Hancock County. A subsequent cold winter seemed to knock their numbers back.

But, this year hairy crazy ants were discovered in Jackson County. Whether this new population is from the Hancock County ants or is a separate infestation is unknown.

This illustrates one of the factors that make these ants such a concern. Hairy crazy ants do not construct mounds; they lurk under leaf litter, in cavities, in walls, etc. At first glance, an area may seem ant-free, but look down and the ground appears to be moving with millions upon millions of ants.

They appear in such large numbers because of their communal nature. One area can support numerous nests and queens because populations do not compete; they cooperate. Wipe out a nest, and millions of ants from other nearby nests quickly take their place.

The only good news when it comes to hairy crazy ants is they pose little health risk. They do not sting like fire ants, and researchers say their bite is insignificant.

The real threat is to property, infrastructure and ecosystems. Hairy crazy ants appear to be attracted to electrical equipment, and can quickly cause shortages and outages.

Those problems have not been  reported in Mississippi – yet. Researchers here, though, are watching Texas with much concern.

In 2002, hairy crazy ants were discovered in Houston, but their numbers have mushroomed. Just this month, Texas added its 19th county to the list of those infested with the ants.

Danny McDonald, doctoral candidate and research assistant at Texas A&M University, said the ants have caused problems throughout the infested area. NASA’s facilities were heavily impacted, they shorted out a system controlling Houston’s waterlines, shorted out traffic signals, etc.

The hairy crazy ant poses the largest threat to the environment. The ants quickly secure an area by driving out other insects and animals. Dr. Blake Layton Jr., entomologist and MSU Extension Service professor, said infested areas are left devoid of other insects and small animals.

MacGown said damage in Mississippi has been largely to homes, and could give no loss figures.

McDonald said damage figures to homes, business and the environment in Texas have been thrown about, but he questions their validity. Damage reports have declined recently. However, he said flatly, “They’re still there.”

Researchers here, in Texas and elsewhere are conducting studies into possible pesticides to control the ants. One problem is attracting them to bait. The ants farm a smaller insect that excretes a sweet substance that the ants eat. Thus, they are not attracted to most of the ant poisons currently available.

McDonald said a carpenter ant pesticide has been shown to work, but slowly. One infested area was treated for weeks in Texas, he said. The first week, 70 percent of the ants were killed, but it took another two weeks to check their numbers completely.

“That’s way too long,” he said.

Layton said experience here in Mississippi has shown that combating the ants takes weeks of multi-prong efforts that include baits and perimeter sprays. He agreed with McDonald – the strategy is inefficient, largely ineffective and complicated.

Layton said research continues, and he is already planning a presentation next January to give the latest on the pests and possible defenses against them.

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