Some say it started with the Great Swarm. The Great Swarm started shortly after the second decade of the 21st century began, but rats had been the most heavily used laboratory animal since the middle of the twentieth century, and this was no less true in the beginning of the twenty-first. Genetic experiments on rats met with little protest from most people, as rats were not seen as especially sympathetic creatures. Some argue today that this lack of sympathy led the humans to their undoing and the fall of mankind from their special place on earth. Certainly some rats argue this today: humans had made quite a mess of things, and it was simply time for mother nature to choose another species as earth's steward.