See PRI’s Top-Ten List for Keeping Pests Out and Kids Safe. Use PRI’s tool, PestSmart, to find low-hazard rodenticide products.
Take the Long-Term View
Rats and mice are not only a nuisance but can also cause property damage and transmit diseases that pose a threat to public health. You’ll know they’ve arrived if you see rodent droppings near a food source or shredded fabric or paper. If you identify rogue rodents, there are several steps to take to ensure permanent removal of these pests.
Removing rodents with traps or poisons will not keep rodents out of your property in the future. The easiest way to permanently keep rats and mice out of your home or business is to prevent access by sealing all entry points.
- Holes near cabinets, closets or doors leading to outside or to crawl spaces.
- Holes around sink or appliance pipes.
- Cracked foundations in the basement or unscreened ventilation holes in the attic, especially in older structures.
- Holes around windows or missing screens in vents or crawl spaces under your property.
Removing food storage or open garbage containers outside will make your property even less attractive to rats and mice. Keep compost piles as far as possible away from buildings. These simple but effective preventative steps save you time and money in the long run.
Once you have blocked the access points, you’ll need to eliminate the remaining rodents. The following sections offer an overview of different treatment options and serve as useful guidance for keeping your property permanently free of rats and mice.
Pest Control Overview
|Seal entry points||Prevent rodents from entering your home or business by permanently sealing holes that allow rodents entry into the building.|
|Remove rodent attractions||Eliminate any source of food or shelter by ensuring that food is securely stored and that surroundings are clean.|
|Signs of infestation||Look for rodent droppings around food, kitchen corners, inside cabinets, or under sinks. Also, look for nesting material such as shredded paper or fabric.|
|Traps||Snap and electronic traps are preferable. Be cautious with live traps as rodents might urinate and increase the risk of spreading disease.|
|Rodenticides||Only use rodenticides if other methods fail. Use the lowest toxicity products to avoid poisoning children and pets.|
Low Impact Approaches
Benefits of Using Traps
Using traps instead toxic poisons offers visual confirmation of a captured rodent and allows you to better gauge the effectiveness of treatment. You are also able to dispose of rodents immediately rather than dealing with the foul odor of rotting carcasses inside your walls or out of reach. Most important, using traps allows you to avoid rodenticides, which pose a greater threat of exposure to children, pets, and non-target wildlife, including endangered species. Often, successful rodenticide treatment requires multiple feedings of poison, which increases the chances of unintended exposure to natural predators like cats or dogs.
|Snap Trap||This is the oldest type of trap and uses a spring-loaded bar to kill a rodent on contact. Some modern snap traps prevent risk to children and pets by enclosing the device in a plastic box.|
|Electronic Trap||This battery-powered trap delivers an electric shock that kills rodents quickly. This is a newer type of trap, and models are available for both rats and mice.|
|Live-Animal Trap||This is a catch and release system that avoids killing a rat or mouse. Some states prohibit releasing rodents into wild. The Center for Disease Control (CDC) warns that captured rats or mice might urinate and increase risk of spreading disease.|
|Multiple-Catch Live Mouse Trap||This is a catch and release system that allows for capture of multiple mice. See warnings for the live animal trap above.|
|Glue Trap||Glue traps are not recommended because the adhesive plate that is used to capture rodents can also trap birds, baby animals, lizards and even pets. These traps also cause undue suffering to rodents. The CDC warns that captured rats or mice might urinate and increase the risk of spreading disease.|
Review all your options before deciding on a treatment plan. If you decide to work with a pest control professional, be sure the company is Ecowise or GreenShield certified and familiar with Integrated Pest Management techniques.
Potential Consequences of Rodenticide Products
Recognize that when you use rodenticides, you should be ready to deal with these potential consequences:
- Rodents are likely to die in locations where they cannot be retrieved. The smell of a dead animal will persist for several weeks to several months.
- If you or your neighbors have cats or dogs, they may die or become acutely ill from eating poisoned rodents.
- Predatory birds like hawks, eagles and owls and mammalian predators such as foxes and coyotes may die from eating poisoned rodents.
Precautions to Take When Using Rodenticides
If you determine that rodenticides are necessary, take these precautionary steps to reduce the potential for adverse effects:
- Indoors, place rodenticide bait stations only in locations that are completely inaccessible to children and pets—inside walls, under heavy appliances, or in enclosed crawlspaces.
- Once all signs of rodents are gone, remove bait stations promptly.
- Always read and follow the label instructions on the pesticide product. The label is the law and you could be liable for any damage resulting from not following the label instructions.
- Use only US EPA approved products (see Regulatory Update below for details).
Rodenticide baits are formulated to be lethal to small mammals, and are therefore not selective for the target species. As a result, all baits pose a high risk of primary poisoning for non-target animals that might eat the bait, including children, pets, birds, and other wildlife. The first-generation anticoagulants listed in the first table below pose slightly less risk to mammals that only occasionally feed on one or just a few bait pellets. This is due to the fact that first-generation baits are metabolized more rapidly, and generally non-target mammals must consume several pellets over several days to receive a lethal dose. Comparatively, the second-generation rodenticides described in the second table below are more acutely toxic and have a higher risk of severe unintended poisoning for children, pets, and other non-target wildlife.
US EPA indicates that brodifacoum and difethialone are the two highest-risk rodenticides for birds or non-target mammals. Bromadiolone and diphacinone are a close second, and zinc phosphide is also high risk.
|First-Generation Rodenticides||Types||Acute Oral Toxicity||Primary Poisoning Risk||Secondary Poisoning Risk|
|Chlorophacinone||Anticoagulant, multiple dose treatment||High||Low (birds and mammals)||Low (birds), High (mammals)|
|Diphacinone||Anticoagulant, multiple dose treatment||High||Low (birds and mammals)||Moderate (birds), High (mammals)|
|Warfarin||Anticoagulant, multiple dose treatment||Moderate to high||Low (birds), Moderate (mammals). Highly toxic to cats.||Moderate (birds and mammals)|
|Second-Generation Rodenticides||Type||Acute Oral Toxicity||Primary Poisoning Risk||Secondary Poisoning Risk|
|Brodifacoum||Anticoagulant, single dose treatment||High||High (birds and mammals)||High (birds and mammals)|
|Difethialone||Anticoagulant, single dose treatment||High||High (birds), Moderate (mammals)||High (birds), Moderate (mammals)|
|Bromadiolone||Anticoagulant, single dose treatment||High||Moderate (birds), High (mammals)||Moderate (birds and mammals)|
|Rodenticide||Type||Acute Oral Toxicity||Primary Poisoning Potential||Secondary Poisoning Potential|
|Bromethalin||Non-anticoagulant, single dose treatment||High||Low (birds and mammals)||Low (birds and mammals)|
|Cholecalciferol||Non-anticoagulant, multiple or single dose treatment||High||Low to moderate (birds and mammals)||Low (birds and mammals)|
|Zinc phosphide||Non-anticoagulant, single dose treatment||High||High (birds and mammals)||Low (birds and mammals)|
Regulatory Updates on Rodenticides
On November 2, 2011, US EPA initiated a cancellation order to remove certain consumer-use mouse and rat poison bait products from the market. These 20 mouse and rat poison products are formulated as loose baits, or as pastes or blocks, that allow access by children and pets. Some of the these products contain the second generation anticoagulants that pose particular hazards to non-target wildlife as well. US EPA notes that:
These 20 rodenticide products generally cause unreasonable adverse effects on the environment, particularly since new rodent control products that meet the Agency’s safety criteria are now widely available, effective and affordable, and pose significantly less risk to people and the environment.
Although EPA has issued a cancellation order, some manufacturers of these products have refused to voluntarily pull these products from the market and replace them with less risky products in enclosed bait stations that will help protect children, pets, and wildlife from rodenticide poisoning. In the interim, EPA has published a list of these hazardous products. Be sure that any rodenticides you purchase are NOT on this list.
UPDATE***On February 5, 2013, EPA published in the Federal Register its notice of intent to cancel the federal registrations of the 12 rodenticides still marketed by Reckitt Benckiser which fail to comply with EPA’s 2008 mitigation measures. On March 6, 2013, Reckitt Benckiser filed formal objections to EPA’s decision and requested a hearing before an EPA Administrative Law Judge. The EPA will hold a formal hearing on the cancellation of the Reckitt Benckiser products, which should conclude by the end of 2013.
On May 30, 2014, Reckitt Benckiser LLC agreed with the US EPA to phase out production of these products and to stop distributing them nationwide by March 31, 2015. These products should be removed from the California store shelves and will no longer be available to consumers after July 1, 2014.
References and Additional Resources
- The Safe Rodent Control Coalition: A resource center that provides guidelines and tips to help you manage rodents safely, effectively, and affordably.
- University of California, Davis IPM Online: Pests of homes, structures, people and pets.
- Center for Disease Control and Prevention: Information on disease hazards posed by rodent infestations.
- National Pesticide Information Center: Provides objective, science-based information about pesticides to enable people to make informed decisions about pesticides usage.
- US Environmental Protection Agency:
Last updated on 2/11/2016