He bred his mosquitos in a bio-containment lab and he also used a species that's not native to the US so that even if some did escape, they'd just die off, there'd be nothing for them to mate with.
Dia membiakkan nyamuknya di lab bio terisolasi dan dia memakai spesies yang tidak berasal dari Amerika jadi meski beberapa lepas, mereka akan mati, karena tak ada pasangannya.