Some people feel that science cannot do this. However it was done already it is just that the public opinion is against it. As soon as that opinion slackens, this will be done publicly rather than secretly. And if it was done to rats or some other species successfully, that means that it was done to all other animal species which are similar, including the humans.

It is inevitable. And we must remember that at the end of the day, Nature functions through human beings to do things which are against Nature itself or which excell or go beyond what nature did.

We are so trapped into the idea that bad humans (according to our individual judgement) are acting against Nature, that we cannot see that Nature itself sponsons these bad actors. Nature itself endorses and takes pride in what they do.