If someone is bitten by a poisonous snake, call a doctor immediately. Eliminating rats and mice from an area often discourages snakes. Remove snakes' hiding places. Get rid of lumber piles, trash piles, high weeds and grasses, and debris. Block openings where snakes might enter buildings.
Snakes can pass through extremely small openings and usually enter near or below ground level.
Be sure doors, windows, and screens fit tightly. Search walls and floors for holes or crevices. Plug spaces around pipes that go through outside walls. Fasten galvanized screen over drains or ventilators, or over large areas of loose construction. There are no sprays, dusts, or poisons that have legal registration for use around homes or farms to repel or kill snakes.