It’s a warm, spring day. You’re sitting under a tree snacking on a bag of potato chips, when a breeze tickles your nose. You sneeze, sending a soggy crumb into the grass where it bonks an unsuspecting ant on the head. Unfazed, she nibbles the chip, then heaves it over her shoulder and carries it back to the colony. Little does she know that, during its brief flight from your mouth, this sticky glob picked up a fungal spore that is deadly to ants. Within a day she’ll be sick, within two she’ll be dead.