When spring finally sprung in 2006, a plague of 90 yellow jacket “super nests” the size of a Volkswagen Beetle formed on the sides of homes, cars, and sheds across Alabama. Now, The New York Times reports, they’re back. Normally, yellow jacket nests are much smaller and die out in the winter, leaving the queen to start a new colony come spring. This year, however, mild winters and abundant food supplies allowed the wasps to survive, accumulating populations of up to 15,000 stinging insects as opposed to the normal 4000 to 5000. These wasps account for almost all stinging deaths in the United States and are able to sting repeatedly. According to officials from the Alabama Cooperative Extension System, the warming climate could make these “super nests” a regular part of spring.