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Pest Information

Tawny Crazy Ant

Tawny Crazy Ant

  • Latin Name: Nylanderia fulva
  • Common Name: Tawny Crazy Ant
  • Other Names: Rasberry crazy ant

Pest Details

Tawny Crazy Ant


These ants previously were believed to be native to the islands of the Caribbean. But, studies in 2012 confirmed that it is a species native to South America. The "common" name disagreement is not completely settled.


Beginning around the year 2000 Florida was invaded by this species of aggressive ant, and in 2002 a similar ant showed up in numbers around Houston, Texas. Subsequent studies of these two ants have determined, in 2012, that they are the same species and are the South American species Nylanderia fulva. The previous genus name of Paratrechina, linking it to other native North American crazy ants, was changed to the genus name Nylanderia. The "common" names are a continuing source of argument, with "tawny crazy ant" most recently proposed. These ants form massive colonies of possibly hundreds of thousands of workers and dozens of queens, and wide foraging trails of thousands of fast-moving workers will overwhelm residential properties. They cannot sting and rarely invade structures, but their sheer numbers and aggressive movements create serious pest problems.


The ants are medium in size and yellow-brown to reddish-brown in color. They have a single node. The antenna is composed of 12 segments and without a “club” at the end. The scape (the long segment attached to the head) is nearly twice as long as the length of the head.

Characteristicts Important to Control:

Successful control is still under study. The problem is the overwhelming numbers of the ants in an established colony. Insect baits do not seem to be highly acceptable to the ants, although they will accept sweet baits that are replaced quickly and kept fresh, as well as placed directly along their trails. The use of non-repellent contact insecticides, particularly those with a good “transfer effect” within the colony, seems to be providing the best management at this time.

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