Tawny Crazy Ants

Published 7:00 am Saturday, June 30, 2018

By Dr.Eddie Smith 

The tawny crazy ant, also known as Nylanderia fulva, is a non-native ant species that has been found in the southern United States, including Hancock, Harrison, Jackson, and Pearl River counties in Mississippi.

The ants are not widely distributed on the Mississippi Gulf Coast, but their presence can be overwhelming in areas that contain a crazy ant population.

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The tawny crazy ant was first documented in Hancock County in 2009, with infestations first recorded in Jackson County in 2010 and in Harrison County in 2012.

In addition to Mississippi, crazy ants have been reported in Texas, Louisiana, Alabama, Florida and Georgia. Researchers at MSU, including those with the MSU Extension Service and the Mississippi Agricultural and Forestry Experiment Station, are collaborating with other southern universities to study the crazy ant and track its movement across the southeast United States.

Tawny crazy ants are known for their erratic movements when foraging, which helped give them their common name.

They are often confused with the Argentine ant, known to most as “sugar ants.” The crazy ant came to the United States from South America and has been causing issues in Texas and Florida for more than 10 years.

The reason tawny crazy ants create so much excitement when they are first encountered in an area is that they build to unbelievably large numbers. Although they do not sting and their nest sites are inconspicuous, tawny crazy ants are a serious nuisance simply because there are so many ants crawling rapidly over the landscape. Heavily infested landscapes will have large numbers of ants rapidly crawling over every square yard of a piece of property. It is difficult to enjoy sitting on the patio on an otherwise pleasant afternoon when you have dozens of ants crawling up your legs.

These ants also invade homes and other buildings in alarmingly large numbers, and they frequently cause malfunctions in electrical equipment.

Of the severely infested homes I have visited personally, all have reported having more than one short or other electrical problem caused by crazy ants. Shorts are the result of accumulations of large numbers of dead ants. One ant wanders into the wrong spot and gets electrocuted or crushed, causing it to release alarm pheromones which attract more ants to the spot.

Although they are easy to kill, the ants are difficult to control. Treated areas are often quickly re-infested by ants migrating from adjacent untreated areas. The surviving ones can travel over the large swath of dead ant bodies without contacting insecticide treated surfaces. Termidor SC, which has a special use exemption in Mississippi’s coastal counties and can only be applied by professional pest control companies, has shown quality results in trials and is one of the best long-term treatments available.