Manage Animal Pests Naturally

Moles

You can’t permanently prevent moles in your lawn. Moles help loosen and aerate the soil but leave ridges and mounds in the lawn. Moles eat insects and grubs, and rarely eat flower bulbs or roots, but can physically disturb plants while they are tunneling for insects.

Use hardware cloth baskets set into the ground to protect young plant roots. Older trees and shrubs are usually safe from disruption.

Replace part of your lawn with garden beds to attract birds and butterflies and hide the mole damage.

Rake down the mole hills. Use the soil to topdress the lawn. It’s free and delivered right to your yard! Pay attention to where the mounds pop up; you're likely to see the moles moving to your neighbors' yards after a few weeks.

Traps are effective, but difficult to use correctly. Traps can be dangerous, so get and follow detailed instructions. Mole trapping is allowed in Oregon and in Washington except for leg hold traps, which are not legal.

Castor-oil and noisemakers have mixed results. Castor-oil repellents may help in the short term. Devices that make noise or vibrations may be effective but likely won't create long-term control. Flooding and fumigating rarely work either, and if it does, nearby moles will move into the vacated tunnel.

Don’t use a pesticide that kills grubs or earthworms. The moles will return, their damage won’t disappear, and in the process you will kill earthworms that help your soil.

More information about moles and mole control. The Washington State Department of Fish and Wildlife developed a fact sheet about moles that can be found HERE.

If you choose to use pesticides, pick a safer product using the Grow Smart, Grow Safe product tables.

Voles

Voles are scavengers. They eat seeds, flowers, leaves, roots, bark, tubers and insects. Voles are brown, about 6 inches long with a long rat-like tail. They live in tunnels just beneath the surface, under grass or ground covers and often use mole tunnels. Damage blamed on moles may be the voles’ work.

Remove shelter. Voles like to hide from predators. You can reduce their numbers by reducing their shelter. Mow or till grassy areas and fields near your garden.

Fence them out. Protect trunks of young trees and shrubs by placing a cylinder of hardware cloth or heavy plastic around the trunk. Surround small plants with cylinders made by cutting the tops and bottoms from bottles or cans.

Repellents can help. Chemical and natural repellents need to be applied frequently and voles can become accustomed to the smell. Success is measured by the reduction – not total elimination – of damage.

Be careful with baits or traps. Poison baits are hazardous to other wildlife, children and pets. Ordinary mouse traps may be effective for small numbers of voles. 

If you choose to use pesticides, pick a safer product using the brand-name product rankings in the Grow Smart, Grow Safe product tables.

Rats and Mice

Rats and mice cause problems when they find a way into your home. They carry diseases and can also damage structures.

Seal openings. Close any hole larger than the end of your pinkie finger with materials that rodents cannot chew through. Use quarter-inch hardware cloth, copper wool or mesh, sheet metal, or mortar.

Remove food and nesting materials. Keep food, food waste, pet food, and seeds in rodent-proof containers. Food composters should be rodent resistant with a lid, floor and no holes or gaps larger than 1/4 - inch.   

Trap rats and mice. Trapping can be a safe and effective method to control rats and mice. Use snap traps in secluded areas and keep away from areas used by children and pets. Place them along walls where droppings are found with the side with the baited trigger closest to the wall.

Be careful with baits. Chemical baits can be effective in managing rats and mice but can poison pets, so they are safest if used in bait stations. Poisoned rodents may die in hard to reach areas, creating odor problems. Poisoned rodents may get eaten by other birds or animals causing their death as well.

If you choose to use pesticides, pick a safer product using the brand-name product rankings in the Grow Smart, Grow Safe product tables.

Deer

Deer eat garden plants, sometimes all of them! They also damage trees by rubbing against them and chewing on branches.

Fence them out. A single fence needs to be at least seven feet tall. A parallel set of shorter fences can work too. Keep the gate latched.

Use plants deer don’t like to eat. Use deer-resistant plants. See the Sunset Western Garden Book for useful lists, or ask your local nursery. Be prepared to experiment.

Try repellents and noisemakers that repel or frighten deer. They can become ineffective once the deer get used to them so change products often, and reapply after rains.

More information about deer and deer control. The Department of Fish and Wildlife have developed fact sheets on invasive animals that can be found HERE. A fact sheet specific to deer can be found HERE.   

Birds

Many birds help control pest insects but some will eat ripening fruit and tender vegetables.

Use netting. When fruit is ripening, drape netting over trees and bushes. Be sure it reaches the ground or is gathered around the trunk. Netting works on crops like figs and blueberries.

Use nesting or roosting barriers. Angled barriers, screens and wire barriers make it uncomfortable for birds to nest or roost on ledges and building peaks.

Reflective tape. Ribbons of reflective tape (mylar) can be placed around the garden or in a newly seeded lawn to help scare birds away from the area.

Scarecrows. Scarecrows can be effective to scare away birds, especially if they are connected to a motion detector and sprinkler that is activated when birds are present.

Try a repellent. Methyl anthranilate, derived from grape skins, is registered for home use on a variety of crops.

Critters are smart and not easily outwitted. For all of these pests, determine how well one method works before you try another. You may have to use several different control methods. Success may be determined by many factors.

Use pesticides as a last resort

Check the label for use and caution statements. It is illegal to use poisons against some animals, even if they are behaving like pests. Keep using non-toxic methods and over time you can reduce pest numbers and the damage they cause.