Fish are being used to control malaria in India with remarkable success.
(They introduce species of fish that like eating mosquito larvae into the kind of ponds, rivers and wells where mosquitoes lay their eggs. The eggs hatch, and the fish eat the larvae. The mosquitoes which transmit malaria have virtually been eradicated from some areas and according to scientists who presented the results of these pilot projects at the Indian Science Congress in Chandigarh, the number of malaria cases each year in India is falling.)