Salt. Ants taste with receptors on thier feet. Walking on salt is painful to them. Smear some salty water and let it dry. No ant scout will ever cross the l

Salt. Ants taste with receptors on thier feet. Walking on salt is painful to them. Smear some salty water and let it dry. No ant scout will ever cross the line. Ive used that trick countless times to keep ants off of counters or from crossing open doors in summer.