The red imported fire ant is one of the world’s most invasive species . Its sting delivers a burning poison that kills living tissue. Together groups of ants devour deer fawns, baby birds, reptiles, and almost any other source of protein they can get their mandibles on. They form acres of crisscrossing tunnels with thousands of cooperative workers. And their territory has steadily been spreading. The fire ant’s story is in some ways the opposite of what the insect world as a whole is experiencing. Measuring bug populations is an imperfect science—they’re small, mobile, and hidden. But they are undoubtedly shrinking, due to habitat destruction, climate change, and other human-driven trends. A German study found a 75 percent decline in insect biomass between 1989 and 2017. Another German study found that the butterfly population decreased from 117 species in 1840 to 71 species in 2013. And a 2014 Science review foun...