To be fair, as someone who walked into one of these masses during the Baytown flood of the 90's (back when the San Jacinto caught on fire, that one), I'll take screaming cows, snakes, and rabid raccoons over floating masses of fire ants. All the former can be shot or kept away with a stick, not to mention seen from a distance. Those ant rafts can sneak around between other floating detritus and catch you by surprise, and there is no defense once they catch you.