She asked him how long the butterflies lived, and his answer was baffling: generally about six weeks. The ones that lived through winter lasted longer, a few months, by going into something like hibernation. “Diapause,” he called it, a pause in the normal schedule of growing up, mating, and reproducing. Somewhere in midlife, the cold or darkness of winter put them all on hold, shutting down their sex drive until future notice.
