Mosquitoes spread diseases like malaria, and they are rapidly becoming resistant to the insecticides used to control them. So scientists are looking at the potential of using a genetic technique, called a gene drive, to solve the problem. This involves engineering a gene-editing system into the insects that targets and inactivates a gene called dbx - or doublesex - that is needed for the insects to develop normally. Critically though, only female mosquitoes, which are also the ones that bite, are affected by the change. This means that males are left unaffected and can spread the genetic modification through the population; but affected female mosquitoes are unable to reproduce, and within 8 generations, the population crashes to zero. Chris Smith heard how it works from Imperial College's Andrea Crisanti...