One of the effects of the flooding caused by hurricane Harvey is that fire ants are now on the move. When their territory is flooded, fire ants will leave their underground nests, link their limbs with each other, and harness the power of surface tension to form floating rafts made of ants. Floodwaters in Texas have plenty of these rafts, as you see in the picture above from Pearland, Texas. Below, the fire ants virtually cover the water in Cuero.
Meanwhile, in Cuero, the river has brought my aunt all of the fire ants. Yes, those are all (of the) fire ants. pic.twitter.com/dEibWYxAdl— Bill O'Zimmermann (@The_Reliant) August 29, 2017
Entomologist Linda Bui studied fire ants after seeing the damage they did in New Orleans to people who waded through floodwaters after hurricane Katrina in 2005.
The episode stuck in Bui’s head, and later, she investigated the venom of flooded fire ants. The study, published in 2011, found that flooded fire ants deliver higher doses of venom because they have 165 percent as much venom inside them as normal fire ants. The flooding made them more aggressive and dangerous. It is also important, she says, to be careful during post-hurricane cleanup. Piles of debris can act like islands, where fire ants have congregated during the flood.