Rodent Control

Raptors and Rodenticides: A deadly combination

THERE IS NO SAFE RAT POISON! Do not take the word of pest control operators - do your own research by looking up the Material Data Sheets for the active ingredient in any pesticide or rodenticide that a pest control company recommends! Commercial rodenticides contain an anti-coagulant rodenticide called brodifacoum (broh-dif'-a-coom) that causes secondary poisoning when raptors consume rodents that have been poisoned. In studies in both California and New York, brodifacoum was found to account for 80% of the secondary poisonings by rodenticides, even though it accounted for only 20% of sales. Brodifacoum is found in the following commonly used products: D-con, Talon, Havoc. It is extremely dangerous to birds through secondary exposure. It can harm pets as well if they consume a poisoned rodent. It is marketed as a "single feed" rodenticide, BUT the rodent takes several days to die and during that time it can continue feeding on the poison, so that is extremely toxic if eaten by a predator. The poison causes thirst which causes the rodent to go outdoors in search of water and this is when it is likely to get preyed on by raptors or cats.

Brodifacoum and other commonly used rodenticides are currently under review by the Environmental Protection Agency (EPA) due to concerns about harmful effects on wildlife and the accidental poisonings of pets and children. There is NO safe rat poison that can be used around pets. Rodenticides are designed to kill. Treat any statement that products can be "safely" used with caution. (Barn Owl Trust, United Kingdom)

The Environmental Protection Agency has proposed implementing restrictions on the use of these poisons and received hundreds of public comments on its proposed mitigation, and the decision was due in 2007, but has continually been delayed. WildCare has had patients come in with suspected brodifacoum poisoning. In July 2007, two juvenile Cooper's Hawks were found dead in a wading pool in Berkeley. Both tested positive for rodenticide poisoning! Accidental or not, the death of raptors by use of rodenticides can be a Federal offense under certain circumstances. More importantly, raptors are a keystone species of the natural food web. The use of poison can cause the natural balance to actually tip in favor of the pest, as happened in the Mexican state of Chihuahua when rat poison killed cats and wildlife that preyed on rats, resulting in the village of Atascaderos being over run with rats.

If you think poisoning a rat is no big deal, please read this story and imagine that instead of being about a rat, it's about your cat or your dog, or your child, or a beautiful coyote, hawk, eagle, or owl. Read exactly what happens to a creature that eats rat poison: in PDF or HTML format. Only one product has been available that kills rodents without causing secondary poisoning to other creatures: Rodetrol. Unfortunetly, this product is currently unavailable as it has been pulled from the market for "reformulating" and we have not been able to get any information on when it will become available again. This product is effective, especially when mixed with an attractant like peanut butter. Currently, it can be found only on e-Bay. Rodetrol does not use poison - it interferes with the unique water absorption system of rats.

Rodents are an important link in the food chain for many species of wildlife in addition to hawks and owls. Secondary poisoning has been documented in such top predators as mountain lions in Ventura County, CA prompting severe restrictions on the use of poisons in public parks and open space. There are native rat species that belong in the environment, such as Wood Rats (aka Pack Rats), as well as the non-native roof and Norway rats that we are more likely to see in or around our buildings. Dusky-footed Wood Rats should never be persecuted or poisoned as they are the favored prey of the endangered Northern Spotted Owl, and are not generally found in or near human habitations. Oppossums are also very likely to eat any rat poison placed out doors. Poisoning rodents, including gophers & moles, destroys the balance and can make rodent problems much worse. If you are seeing rats/mice outdoors - consider the philosopy of Live and Let Live examine your yard to see what food and harborage you may be providing for rats. Exclusion and sanitation are the most effective means of solving a rodent problem in or around the home!

What you can do to help raptors & solve rodent problems

If you have a rodent problem, try non-chemical methods first. The key aspects are:

  • Remove piles of yard debris, trash, construction waste, etc. where rats or mice could make homes.

  • Eliminate food sources. Don't leave pet food outside. Keep wild birdseed and other materials rats or mice may eat (such as some organic fertilizers) in rodent-proof containers. Collect and remove fallen fruit from fruit trees in the yard.

  • Exclude rodents from your home. Rodents can squeeze through amazingly small holes - 1/4 inch for mice and 1/2 inch for rats. Go around the outside of your house looking for openings and seal them with metal, hardware cloth, mortar, concrete, or Stuf-fit Copper Mesh Wool, which can be found online or at hardware stores.

  • For more detailed suggestions on exclusion and sanitation to reduce rodent problems in and around the home Download and print this flyer (pdf file).

    If you are having any kind of conflict with wildlife, please don't call pest control companies or trappers - they make a living killing wildlife! Please contact one of the following humane resources:

    WildCare Solutions - Protecting their home and yours! 415-453-1000

    Information on wildlife conflict resolution

    San Francisco Rescued Orphan Mammal Program (SF ROMP)

    If these methods do not help, and you feel you must kill rodents inside a building, consider the Rat Zapper. Information available at kills rodents with no harm to the environment, your pets, or your family. For indoor use only! "...I got a battery powered RatZapper from our Ace Hardware, and killed nine rats in five days. I have no rats now." Bob Twiss Ross (San Francisco Chronicle, 1/14/06). It is also possible to use catch and release traps for rodents instead of killing them, followed by exclusion to avoid having to deal with the problem again later. You could also make your own humane, catch-and-release, mousetrap!

    Below is a list of wildlife friendly pest control operators in Marin & Sonoma counties. Please note that if rodents must be exterminated, the Hungry Owl Project recommends only the Rat Zapper, or snap traps (these work best when baited with peanut butter & oatmeal) used inside bait boxes with openings small enough to keep out non-target animals, and only for use inside buildings. Recommended bait: Skippy Super Chunk peanut butter. (It must be the Skippy brand - lots of sugar.) Ask the Bugman recommends baiting traps with Slim Jim. Use of traps outdoors can kill non-target wildlife and pets.

    Additionally, HOP recommends AGAINST the use of sticky traps to catch rodents. These traps are horribly cruel, and when used outdoors, can catch other non-target animals, such as birds. The country of Australia has actually recognized how cruel they are and is considering outlawing them! Where to order humane mouse traps for catch and release of rodents.