Screwworms are coming—and they’re just as horrifying as they sound

The US is bracing for a potential screwworm invasion from Mexico as officials release weaponized adult flies near the border to combat an infestation. These New World Screwworms, which are highly destructive to humans and livestock, were previously endemic in parts of the southern U.S., Central America, and South America but have recently been detected in Mexico. The Department of Agriculture has relied on a sterile insect technique before to curb their spread, involving massive efforts to kill or inhibit the species, but this time they’re using flies that cannot reproduce to stop an ongoing infestation.