Despite what others say, it CAN kill scorpions if applied tight spaces (like corners and crevaces of cinderblock walls where they love to hide). However, the main purpose is to kill the crickets, earwigs, and roaches that they eat.
I spray every month in the 6 hottest months. You can lower the dosage when you are seeing less bugs late at night. Use a blacklight to get an idea of how many scorpions are out to see if it is working.