Fly vs. wasp: Stealing a defense move helps thwart a predator

Many flies are plagued by parasitic wasps, which lay their eggs in fly larvae, turning them into surrogate wombs for wasp larvae. One common fly has successfully fought off its wasp predator by stealing a gene from bacteria that originated in bacteriophage. Biologists inserted that gene into other flies, making these flies resistance to wasps. This discovery shows that horizontal gene transfer may be more common in animals that people thought.