Ivan Illich ( Limits to Medicine: Medical Nemesis, the Expropriation of Health ) writes about the unintended effects of insecticides in Borneo: “Insecticides used in villages to control malaria vectors also accumulated in cockroaches, most of which are resistant.  Geckoes fed on these, became lethargic, and fell prey to cats.  The cats died, rats multiplied, and with rats came the threat of epidemic bubonic plague.”

To stop the dominoes, “the army had to parachute cats into the jungle village.”