Discover Your Island

Rodents and Vector Control

Why control mice and rats?

  • Mice and rats, whether dead or alive, spread disease.
  • They contaminate our food with urine and droppings;
  • start fires by gnawing on electric wires; and
  • destroy keepsakes and valuable possessions by gnawing.

How to identify a rodent problem?

  • Rodents are generally most active at night. They leave telltale signs, including:
    • Rub and gnaw marks;
    • Burrows and tracks; and
    • Droppings.

How to get rid of rats?

  • Rats are like people. They need a place to live and food to eat. If you remove their shelter and food, rats CAN be eliminated.

Here's how...STARVE THEM!

  • Place bird food in a feeder, not on the ground.
  • Clean up spillage daily!
  • Use metal trash cans or approved plastic with tight-fitting lids.
  • Keep trash cans covered!
  • Clean up fallen fruits and nuts from the ground.
  • Remove pet food dishes and leftovers promptly after feeding.
  • Clean up animal waste frequently!

Remove shelter!

  • A dilapidated shed or automobile is an invitation to rats. Repair or remove them!
  • Rats can jump up to three feet and climb wires and pipe very well. Be sure to seal any openings to the house, even above ground level. This includes the garage,openings in the foundations, and the basement floor drain. Keep doors and windows screened with half-inch mesh hardware cloth.
  • Store lumber, firewood or other materials well off the ground.
  • Repair any breaks in the sewer line which connects your home with the main sewer system.

Trap them!

  • Spring-loaded traps are effective indoors where poisons may pose a threat to people or pets, where poisons are impractical due to the proximity of food, or where recovery of the poisoned rats would be difficult.
  • Trap or glue boards are preferred indoors due to the odor caused by poisoned rats.
  • Traps may be baited with peanut butter or with partially cooked bacon.
  • Mice may be trapped by binding nesting materials to spring-loaded traps. Follow the directions on the trap package for proper placement. Glue boards are another alternative.
  • Any trap should be used according to package instructions!

Poison them!

  • An effective rat poisoning program requires a fresh, dry supply of bait that is readily available. To kill rats in the shortest time possible, first eliminate all other sources of food, forcing the rats to accept the poison as their only food.
  • Recommended Poison Rat Baits : Use any properly labeled, EPA approved poison rat bait. Contact your local hardware or garden shop.

Examples of different active ingredients:

  • Multiple dose anticoagulants: Diphacinone, Warfarin, Pival
  • Single dose anticoagulants: Brodifacoum, Rozol
  • Nerve impulse interceptors: Bromethalin
  • Calcium mobilizers: Cholecalciferol

As long as rodents are eating the bait, the poisoning program should continue. With some poisons, "bait shyness" may develop after several rats have died, so it may be necessary to switch to another poison to eliminate the remaining rats.

For safety and maximum effectiveness, be sure to follow label directions carefully and wear gloves when using any poison. Always be careful to locate rat bait out of the reach of children and pets! Final tips on rodent control

  • Never touch rodents, objects they have contaminated, or rodent poison.
  • Always wear disposable gloves when handling rodents, rodent bait or when cleaning rodent soiled areas.
  • Avoid stirring up and breathing dust in these areas.
  • Wear a mask to avoid breathing dust particles contaminated by rodents.
  • To eliminate dust, use a disinfectant to dampen soiled nesting material and droppings before sweeping.
  • Wash your hands afterwards.

The House Mouse (Mus musculus)

  • light to dark brown, with prominent ears and eyes. Adults leave rod-shaped droppings approximately one eighth inch long. Life span is six months to a year, with an average of eight litters of five to six "pups" per litter. The house mouse lives in walls, cabinets, subfloors, crawl spaces and furniture, usually within thirty feet of food source. It will eat any food but prefers grain. A nibbler, it eats small amounts of food from many sources. Water requirement depends on food. Grains, dog food and cereal have enough moisture, so no water source is needed, but mice do take water when available. Habitual gnawers and collectors of nesting material, mice are generally curious.

The Norway Rat (Rattus norvegicus)

  • heavy set, light brown to almost black; droppings are capsule shaped, about three quarters of an inch long. Lives about one year, six to twelve "pups" per litter, up to seven litters per year. Rats burrow in the ground, under buildings and rubbish; usually living well within 150 feet of food and water source. Rats require about one ounce of food a day and a half ounce of water. They feed habitually on familiar food, preferring meats and grains, and are cautious of new items or new food.

Source: Saint Louis County Department of Health