We all have our limits on what we will and won’t tolerate when it comes to pests in the home and garden, but there are good reasons to control rodent populations, says master gardener Steve Griffin.
Rodents — rats, mice, moles, gophers, tree squirrels and ground squirrels — can cause damage to infrastructure and spread diseases.
Here are some of Griffin’s tips on keeping them from becoming too much of a pest.
The first step is to identify what type of rodent problem you have. Knowing what animal is eating your plants, digging holes in your yard or snacking on food in the kitchen will determine what steps you take to control it.
Take a good look at your home and yard. Are you inviting the pests in by leaving pet food out, feeding birds or growing food?
Next, look at changes you can make to discourage rodents from visiting. You may need to start storing food in containers, removing food after pets have eaten, and pruning trees away from your home to prevent rodents from climbing onto your roof and into your attic.
Buttoning up entryways into your home also will help eliminate the problems inside, Griffin says. Outside, look at fencing and other exclusions.
If you decide to take lethal steps to control rodents, choose your tools carefully. Never use poisons, which often unintentionally kill other animals.
If you use traps that capture animals alive, kill them humanely or release them in a place where they will not do damage to native birds or other wildlife. See http://wdfw.wa.gov/living/nuisance/trapping.html for guidance.
Rats and mice
There are two species of rats — roof rats and Norway rats — that live with humans.
Norway rats usually are found on the ground floor. They have heavier bodies and tails that are shorter than their bodies.
Norway rats prefer trash and wood piles, and basements.
Roof rats are great climbers and are nest above ground in trees, walls, cabinets and false ceilings. Their tails are longer than their bodies.
Mouse populations rise and fall with weather and the availability of food.
House mice are attracted to pet food, snacks left in drawers, and pantries with plenty of food in cardboard or light plastic wrappings.
Mice will nest in walls, drawers and cabinets, and build nests of almost any materials.
Rats and mice spread disease through fleas, feces and urine, which they leave as they search for food.
Good housekeeping can keep most rat and mouse populations down. Repair door sweeps, plug entry holes, and screen attic vents and the vents around building foundations. Trim limbs and landscaping away from the roof line and foundation walls. Pick up pet food, and seal food in sturdy plastic or metal containers.
Trap mice and rats with snap or electronic traps. Do not use poisons.
Bait a rat trap with nuts or sticky candy tied to the trigger with twist-ties, wire or zip ties. Bait a mouse trap with peanut butter or a soft candy such as caramel.
Moles
Moles are insectivores and don’t eat plant material. Any damage they do is to the appearance of your garden or yard, and occasionally they may kill a plant when they disturb the soil around plant roots.
Moles are difficult to capture and probably should just be left alone.
You can bury mesh, as you do with gophers, to exclude moles from the yard. Trapping rarely works.
Voles
These mouselike creatures hardly ever enter dwellings, but they can do some damage in the garden and landscape. Their populations rise and fall with great regularity.
Voles are active day and night, feeding on grasses, veggies, bulbs, roots and tree bark. Unchecked, they can girdle a young tree and kill it by eating through the bark into the cambium.
Protect young trees with a guard at the base and keep ground covers away from the tree trunk.
Trap with unbaited mouse traps, placed in the pathways of the voles.
Squirrels
Tree squirrels can be a nuisance, feeding on fruit and vegetables, and nesting in attics. They also can vector diseases through fleas.
Ground squirrels are extremely destructive, digging under roads, fences, foundations and utilities. They feed on vegetables and can destroy a garden fast.
Ground squirrels dig large dens with open holes. They also vector diseases through fleas.
Control ground squirrels with wire fences, above and below ground, and with an electric shock wire along the top of the fence.
Hawks, coyotes, foxes and bobcats feed on ground squirrels, so don’t use poisons as a method of controlling the population.
Exclusion and deterrents are the best ways to handle pests.
