Use steel wool to stop mice
Seal cracks or holes in wall and baseboards with steel wool, which mice and other household pests can’t chew through.
Stop ants with a natural barrier
Sprinkle a narrow, unbroken trail of cayenne pepper, black pepper, or salt across their path. Or draw a line with chalk. If that doesn’t work, here are more great examples of how to get rid of ants without pesticides.