Black Flag Spider & Scorpion Killer is formulated to kill large spiders and scorpions. Kills on contact. It kills black widow, brown recluse and wolf spiders. Indoors - Use to control spiders, scorpions, ants*, cockroaches, silverfish, crickets, sowbugs, firebrats and other common household pests. Outdoors - Use to control spiders, scorpions, ants*, brown dog ticks and crickets.