Christian Rudder, a co-founder and general manager of OkCupid, said that when his dating site recently bought and redesigned a smaller site, they witnessed not just a sharp decline in bots, but also a sudden 15 percent drop in use of the new site by real people. This decrease in traffic occurred, he maintains, because the flirtatious messages and automated “likes” that bots had been posting to members’ pages had imbued the former site with a false sense of intimacy and activity. “Love was in the air,” Mr. Rudder said. “Robot love.” Mr. Rudder added that his programmers are seeking to design their own bots that will flirt with invader bots, courting them into a special room, “a purgatory of sorts,” to talk to one another rather than fooling the humans.