Why not genetically engineer feral cats to stop them reproducing?

This may be an idea that has been put forward before but which has just occurred to me. It is possible, nowadays, to genetically engineer animals so that when they reproduce the female cat is rendered sterile. This genetic modification is passed on from the male to female. Feral cat colony. Picture in public domain. Therefore, if you introduce into a population of feral cats some male cats who can pass on this modified gene then eventually that colony would disappear and in a very humane way. The technology is called "gene drives". As an alternative to passing on a gene which renders female cats sterile, you could ensure that offspring are nearly always males which would create an imbalance between males and females in a large colony. This also would have the result of reducing the colony's size to the point where it became zero ultimately. I am convinced that it must have been discussed. It is new technology but I don't recall it being discussed in relatio