Entire colonies of stinging insects could become dislodged by flooding, threatening the safety of both humans and animals as they drift toward populated areas.
“When floodwaters come, humans are not the only ones looking for dry ground,” officials from the Alabama Cooperative Extension System warned.
“In areas infested with red imported fire ants, these ants and their colonies can present a potentially serious medical threat to people and animals during and after a flood.”
Red imported fire ants, one of the world’s most aggressive species, are resistant to water and survive storms by clinging together in floating colonies.
Masses of ants may create rafts that resemble ribbons, streamers or large balls.
Rust red in colour, the rafts include all members of a colony: worker ants, winged reproductive males and females, and the Queens at the top of the ant hierarchy.
The amorphous ant blobs have been spotted clinging to fences.
They can remain floating until the flood waters subside and the insects find dry land to reestablish their colony.
Each of the insects have a potentially harmful sting, which may cause lethal anaphylactic shock in a small proportion of the population.
Experts recommend wearing boots, gloves and long trousers in the floodwaters and when clearing debris.
“If ants contact the skin, they will sting. Remove ants immediately by rubbing them off. Ants will only cling to the skin if submerged,” entomologists at Alabama Extension said.
Tropical Storm Cindy came ashore in Louisiana on Thursday, bringing wind speeds of around 50mph, rain and flash flooding.
A 10-year-old boy was killed on an Alabama beach when he was hit by a log.
It was downgraded to a depression as it headed inland but continued to dump heavy rain on southern states.