Mice can transmit pathogens, damage property, and destroy crops, and invasive populations have been known to threaten the biodiversity of islands across the globe ?" but getting a gene drive to work efficiently in mammals has proven to be a challenge. What's new? After five years of research, University of Adelaide scientists have now developed t-CRISPR, a technology that builds on a gene drive found in nature to render mice infertile. The natural gene drive is known as the "t haplotype," and carrier mice pass it down to about 95% of their offspring. T-CRISPR piggybacks on the gene drive to spread faulty copies of a female fertility gene to offspring, rendering them infertile.