Prozap Screw Worm and Ear Tick Aerosol 12oz; Prozap Screw Worm / Ear Tick Aerosol provides wound protection from flies and maggots. Contains 0.5% Permethrin. Contains violet marking dye to indicate treated animals and uniform coverage. Controls maggots, flies, screw worms, ticks (including ear ticks), gnats, lice, and other insects. For use on beef cattle, dairy cattle, goats, sheep, hogs and horses