Crazy ants were first discovered in the Houston area in 2002, where they probably arrived in a cargo shipment.

They have now reached San Antonio and the Rio Grande Valley, and scientists don’t know exactly where they originally came from.

While they don’t bite like their nasty fire ant cousins, they multiply at alarming rates.

They also have the habit of swarming en masse and covering whatever they climb, like pets, people and wildlife.

They even overwhelm and destroy fire ant colonies as they conquer new territory, advancing in all directions rather than in a straight line.

The insects cause the most problems for humans due to their attraction to electronic devices. They can short out computers and household appliances, and have even knocked out control valves on pipelines, costing one company a million dollars for just once incident.

“From an ecological standpoint, when you go out into rural areas where there's an infestation, there's an eerie silence – there's a lack of insects and grasshoppers, a lack of songbirds," said exterminator Tom Rasberry, who first identified the insect in the Houston area.

Their preference for warm, moist regions may limit their expansion northward, but Rasberry believes they might make it at least as far north as Dallas.

Photo: Columbia University