How did they screen for this venom?

Too lazy to read an article that takes about one minute? Sheesh.

    > “We screened 50 venoms, mostly from spiders and scorpions, by applying them externally to the mites,” says Herzig.

    > “We found more than 75% killed the mites within 24 hours. We selected 2 of the most potent spider venoms for further analysis.”