Roof rats are relative newcomers to the Valley of the Sun; they were first detected in the upscale Arcadia district in 2002. Since that time, they’ve migrated all over the Valley, invading from the East Valley to the West. If you want to avoid an infestation of roof rats, there are a few important steps you can take.

1. Keep Your Yard Clean

Roof rats, as well as other rodents, need places to hide and build their nests, and yard litter is great for that. Be sure to rake up fallen leaves under your trees and bushes. Keep fruit trees pruned back enough to see the ground beneath them. Get rid of any wood piles. If you really need to store wood, keep it at least 12” from any walls, and elevate it at least 18” above the ground. Keep your palm trees trimmed. Rats and other rodents will nest in old palm fronds. Roof rats love to make nests in oleanders. Thin out your oleanders and other bushes.

2. Deny Them Food

Fallen citrus fruit is a food and water source for roof rats. Pick up any fallen fruit from the ground right away. Pick up after your dog, and don’t leave any pet food out overnight. Limit or get rid of your bird feeders. If you must have a bird feeder, clean up any food from the ground before nightfall. Inside your home, keep bulk foods in tightly sealed, rat-proof canisters. Keep your garbage cans tightly covered.

3. Seal Any Openings in Your Home

Roof rats can get inside your home through an opening the size of a nickel. Carefully seal any cracks or openings using stucco diamond mesh. It’s readily available at building supply stores, and it’s easy to cut and shape. Look for openings in your exterior walls and near the washer and dryer, the water heater, dishwasher and under the sinks. Use caulk on any cracks, and screen off the sewer stacks on your roof. Stuff steel wool into the air-conditioning lines that come from outside into the attic.

4. Use Traps Strategically

Bait traps with peanut butter and set them in the laundry room, kitchen and outside sheds. Be sure to keep traps away from areas where they can be found by small children or pets. Roof rats in Phoenix are wary of unfamiliar objects; leave the traps for at least a week before moving to another location.

5. Use Poison With Extreme Caution

If poison seems the best option, use a bait station. These are enclosed to keep out to non-target animals. Don’t use poison bait blocks on tree branches. They could accidentally poison cats and birds. Thoroughly seal your home before using poison bait. Otherwise, the rats could come inside your home to die.