What Could Possibly Go Wrong? 

In the Cayman Islands, British biologists are running a science experiment out in the real world. They’ve genetically modified male mosquitos to be sterile, then set them loose in the wild, with the hopes that their fruitless mating with females (the gender responsible for all the biting) will lead to a reduction in population.

Because the sterility can’t be passed on to the next generation, they view this as both limited and safe. Of course, the law of unintended consequences tells us that just about anything could happen.