Rodent and Snake Control After a Flood Safety Precautions And Elimination

Following floods, rats and other rodents may move into buildings to escape floodwaters. Snakes are often forced into places where they are not usually found. Upon re-entering flooded homes or buildings, you will need to be wary of these possibilities. Rats can carry disease and parasites, while snakes may be poisonous or at least frightening. Neither pose serious problems in Wisconsin, but the chance of an incident increases after a disaster.


Because of the danger of rat infestation, use caution when entering flooded buildings:

  • Carry a solid club and a flashlight.
  • Inspect likely hiding places for rats. Check closets, drawers, mattresses, appliances, upholstered furniture, stacks of clothes or paper, dark corners, attics and basements.
  • Be extremely careful when approaching rats. They may be aggressive.

If rats continue to be a problem after floodwaters recede, contact your county Extension agent or professional pest control operator for advice. If you proceed on your own be extremely careful with any rodenticide or trap. To minimize rat problems:

  • Remove trash piles and piles of damaged furniture or equipment. Store materials on platforms or shelves 12 to 18 inches above the ground.
  • Remove food sources. Store food supplies in rat-proof bins or containers. Suspend garbage containers from trees or posts. Remove animal carcasses, as they may attract rats.
  • If you are bitten by a rat, wash the wound with soap and water and see a doctor immediately. Rats may carry diseases and at the least, rat bites can cause infection. If the rat is captured or killed, health authorities may wish to check it for rabies or other diseases. When picking up a carcass, use the inside of a plastic bag to avoid touching it. Double-seal it in plastic and freeze until further notice.

It is important to know what poisonous snakes may be common to your area. Only two poisonous snakes exist in Wisconsin: the timber rattlesnake and the massasauga rattlesnake. Both species are restricted to the southwest quarter of the state. The massasauga is an endangered species and is rarely encountered. Non-poisonous snakes, however, are common and may bite. Remember that all snakes are beneficial to the ecosystem and should not be killed indiscriminately - poisonous snakes included. But follow these precautions upon entering a flooded structure or area:

  • Be alert for snakes in unusual places. They may be found in or around homes, barns, outbuildings, driftwood, levees, dikes, dams, stalled automobiles, piles of debris, building materials, trash or any type of rubble or shelter.
  • Keep a heavy stick or long-handled tool handy. After dark, carry a strong light.
  • Before beginning rescue or clean-up operations, search the premises thoroughly for snakes. Wear heavy leather or rubber high-top boots, and heavy gloves. Use rakes, pry bars or other long-handled tools when removing debris. Never expose your hands, feet or other parts of your body where a snake might be.
  • Explain to children the dangers of snakes during storm or flood conditions and the precautions they should follow. Do not allow children to play around debris.
  • If you kill a poisonous snake, use a stick, rake or other long-handled tool to carry it away for disposal.
  • If you realize you are near a snake, remain still-sudden movements may cause the snake to strike. If the snake doesn't move away from you after a few minutes, slowly back away from it.
  • If someone is bitten by a poisonous snake, call a doctor immediately. If bitten by a non-poisonous snake, clean the wound and watch for signs of infection.

To minimize chances of finding snakes indoors, block openings where they might enter buildings. Snakes can pass through extremely small openings and usually enter near or below ground level. Some other suggestions:

  • Be sure doors, windows and screens fit tightly.
  • Search walls and floors for holes or crevices. Inspect the masonry of foundations, fireplaces and chimneys. Then plug or cement these openings.
  • Plug spaces around pipes that go through outside walls.
  • Fasten galvanized screen over drains or ventilators, or over large areas of loose construction.

Additional resources:

Your county agricultural agent

Related publications:

UW-Extension Publications-

"Snakes of Wisconsin," (G3139);

"The Raccoon," (G3304);

"Skunks: How to Deal With Them," (G3273);

"Meadow Mouse Control," (A2148);

"Tree Squirrels in Wisconsin: Benefits and Problems," (G3522).

Disclaimer and Reproduction Information: Information in NASD does not represent NIOSH policy. Information included in NASD appears by permission of the author and/or copyright holder. More