One method was to attack the breedi

One method was to attack the breeding places of the mosquito. It was known that mosquitoes laid their eggs in water. So, in malaria infested areas work was started on draining marshes, stagnant pools, and trying to ensure generally that there were no areas of water where mosquitoes could breed. Where areas of still water could not be drained, they were sometimes covered with oil or detergent, which made them unable by the mosquitoes.3. One of the more ingenious modern methods of preventing mosquitoes from multiplying is to introduce a different variety of mosquito into an area: when the two varieties mate, the females are infertile. This kind of ‘biological engineering’ has some limited success in the field, but it is not always possible to reproduce laboratory conditions in real life. Since there are over 2,600 different kinds of mosquitoes, the research problems are enormous.