the world health organization began a DDT spraying program which virtually eliminated malaria.But other things began to happen.Besides killing mosquitoes, the DDT killed other insect that lived in the houses,such as flies and cockroaches. These insect were the favorite food of geckos(small lizards).And so when the geckos ate the dead insects, they died from DDT poisoning.Similarly,the house cats ate the dead geckos and cockroaches, and they too died from DDT poisoning. As a result, the rats population rose sharply,and the human population of Borneo began to die from a type of plague carried by fleas on the rats.In order to deal with the emergency,thousands of cats were parachuted into the island,in what was called 'operation Cat Drop'