A gold and brown Swainson's hawk in flight against a blue sky

When it Comes to Rodent Control, Consider Alternatives to Poison

Spring is in the air and rodents may be in your garage, attic, closets, cabinets, tool shed or yard. It’s a busy time for pest control companies and rodenticide sales. But nature can control rodent populations, if you let it. In the natural environment, there is balance. Every creature is prey to some animals and predator to others.

Raptors – owls, hawks, falcons, eagles and vultures – are rodents’ natural predators. If you actively protect them and their habitat, you won’t need to spend money on poisons and put desirable wildlife, pets and children at risk of accidental poisoning. Environmentally friendly tactics (such as providing tall trees that raptors favor) will encourage these birds of prey to hang around your yard and remove rodents for you.

Most raptors use the same nest for many years and some even pass from one generation to the next. Bald eagles are known to have used the same nest as long as 35 years. That makes them an excellent long-term control for rodent populations in the immediate area.

During breeding season, a family of five owls can eat as many as 3,000 rodents! You can encourage them by hanging a nest box on your property, but please don’t do that if you or any of your neighbors are using anticoagulant rodenticides. Remember that poisoned rodents can poison the predators, scavengers and pets that eat them!

Even though the state Department of Pesticide Regulation and U.S. Environmental Protection Agency have restricted public access to the most dangerous rodenticides, all rodenticides – including the types still available to consumers – are poisons that can kill wildlife, pets and children.

Unfortunately, even after stricter regulations on rodenticides were enacted, wildlife continue to be exposed to second-generation anticoagulant rodenticides (brodifacoum, bromadiolone, difenacoum and difethialone). Licensed pest control companies and agricultural producers are still free to use them. If consumers hire pest control companies, they should know that the materials the firms use could poison local wildlife. Only consumers can ensure that it doesn’t. The most effective pest control does not involve chemicals, but sanitation and exclusion.

Like most animals, rodents will congregate and multiply where food is available and they feel safe. The easiest way to discourage them is to remove or modify anything that could make them comfortable. Sanitation is the first step to controlling rodents. For example:

  • Keep your home and yard neat and clean. Don’t give rats places to hide.
  • Remove objects and plants that rodents can hide under, such as wood piles, debris, construction waste, dense vegetation and ground-covering vines like ivy.
  • Pick up fruit that has fallen from trees as soon as possible.
  • Secure your garbage in a tightly sealed can.
  • Seal water leaks and remove standing water that can attract unwelcome animals, breed mosquitoes and waste water.

To remove unwelcome rodents, set traps in secluded areas where they’ve been seen or are likely to travel: close to walls, behind objects, in dark corners, on ledges, shelves, fences, pipes and garage rafters. In areas where children, pets or birds might go, put the trap inside a box or use some kind of barrier for their safety. Check traps daily and wear disposable gloves when removing rodents from traps. Place them in a sealed plastic bag then into your garbage bin for weekly collection. Wash your hands after handling traps or rodents, even when using gloves.

Once you’ve removed mice and rats from inside the building, seal the entries they used to get in: openings where cables, wires and pipes enter buildings, and cracks or holes in the foundation, walls and roofs. Rodents can squeeze into holes as narrow as ½ inch diameter! Use hardware mesh and concrete, plaster or metal whenever possible. At the very least, stuff stainless steel or copper pot scrubbers, or Stuf-fit copper mesh wool into the spaces. All of these are sold online and at hardware and dollar stores.

If you feel you must use “rat poison,” please carefully follow the label directions for all rodenticides. Only use them in small treatment areas indoors or right against building walls in tamper-resistant bait stations, never out in open field or garden areas, where they’re most likely to reach wildlife and pets. Much more information and practical advice can be found on the California Department of Fish and Wildlife’s website at www.wildlife.ca.gov/living-with-wildlife/rodenticides.

A juvenile great horned owl with fuzzy feathers, perched on a weathered board
Juvenile great horned owl. Photo by Phil Robertson

Media Contacts:
Stella McMillin, CDFW Wildlife Investigations Lab, (916) 358-2954
Dana Michaels, CDFW Communications, (916) 322-2420