In the "don't-develop-a-pen-use-a-pencil" science bin we have this BBCnews report on how India is using fish for malaria control. Guppies, even. Seems they have a taste for the skeeter larvae, and in some places have nearly eradicated them.

As someone who was raised in a mosquito-infested river delta, I can only say whatever kills the blasted things must be good.