Cat's Dropped into Borneo

As part of anti-malarial campaign in the northern states of the island of Borneo in the late 1950's, the World Health Organization sprayed DDT and other insecticides to kill the mosquito vector for malaria.

During this campaign, DDT was sprayed in large amounts on the inside walls and ceilings of the large "long houses" that housed an entire village in these areas. As a consequence of this effort, the incidence of malaria in the region fell dramatically.

However, there were two unintended consequences of this action. There was an increase in the rate of decay of the thatched roofs covering the long houses because a moth caterpillar that ingests the thatch avoided the DDT but their parasite, the larvae of a small wasp, did not. Also, the domestic cats roaming through the houses were poisoned by the DDT as a consequence of rubbing against the walls and then licking the insecticide off their fur.

In some villages, the loss of cats allowed rats to enter, which raised concerns of rodent-related diseases such as typhus and the plague. To rectify this problem in one remote village, several dozen cats were collected in coastal towns and parachuted by the Royal Air Force in a special container to replace those killed by the insecticides.