To help prevent roof rats, follow these tips from the Maricopa County Vector Control:

• Get rid of the roof rats’ food supply by harvesting citrus and other fruit.

Pick all fruit (ripe or not) on citrus and other fruit and nut trees and pick up any fallen fruit. Do this promptly and completely. Fruit and nut trees having the most activity are the ones which come in contact with other trees, houses, fences or with power lines running through.

• Donate any excess fruit your family won’t be able to eat to the closest food bank. Next winter, when the roof rats are under control or eradicated altogether, enjoy your harvest, but be sure to pick your fruit promptly and donate what you can’t use. You don’t need to remove fruit trees from your landscape.

• Manicure your landscape. A clean yard is a deterrent.

• Rake under your trees and shrubbery. Prune fruit trees so the ground under them is open and visible. Remove wood piles and brush piles from your yard. Store wood and lumber piles at least 18 inches above the ground and 12 inches away from walls. Thick ground covers should be thinned.

• Keep your palm trees trimmed. Roof rats nest in the skirts of old fronds, as well as in piles of debris and hollow trees.

• Thin out bushes until you can see daylight through them. Oleanders are particularly prone to harbor roof rats in the summer. Thin bougainvilleas as well.

• Don’t feed the roof rats unknowingly.

• Roof rats will eat anything to survive; this includes pet food and garbage.

Don’t leave pet food out, especially overnight. Keep dog feces picked up.

• It would be best to stop filling your bird feeders for the next few months. Otherwise, provide just the amount of bird seed that will be consumed in a day and sweep up fallen seeds on the ground before sunset. Store bags of bird seed in sealed, rat-proof containers.

• Store bulk foods in sealed, rat-proof containers.

• Keep garbage containers tightly covered.

• Strategically place snap traps and bait stations

• Maricopa County does not provide bait stations or traps to the public. Bait stations can be purchased at cost through Barry Paceley at http://www.roofrat.net.

• To prevent rats from entering your property, or to eliminate rats that have already entered your property, set snap traps in your laundry room and garden shed baited with creamy peanut butter. Don’t put much on the bait tab so the rat will have to work at it to get it off. This will ensure that the trap will trip. • Place the traps well away from pets and small children. Roof rats are nervous and cautious of new objects, so leave traps in the same location for at least a week before moving them.

• Bait stations made of plastic, cardboard or metal provide a protected place for rats to feed. They allow you to place poison bait in some locations where it would otherwise be difficult because of hazards to non-target animals.

• Place two bait stations in your yard, 4 feet or higher off the ground. Optimal locations are in your citrus tree and anywhere near potential rat pathways, such as close proximity of wires to house roofs, trees or oleanders.

• It’s important to close the bait station opening in the morning to protect wild birds that might be attracted. Open it up in the late afternoon about sunset.

• The practice of wiring poison bait blocks directly to tree branches causes accidental poisoning of cats and wildlife. Use poison bait blocks only in bait stations and slide the blocks all the way to the back.

• Residents will be responsible for purchasing and placing the bromadiolone poison in the bait station. Read the entire label first and strictly adhere to all instructions, restrictions and precautions.

• Bromadiolone is sold as “Just One Bite” and can be purchased at feed and hardware stores. “Just One Bite” is an anti-coagulant that kills rats in 3-5 days.

• It is important that the resident’s home is properly sealed so the poisoned rat doesn’t enter the house and die, creating a bad odor which may be hard to remove.

What doesn’t work:

• Rats quickly learn safe travel routes through yards to avoid dogs. Cats will kill dispersing juvenile rats, but are rarely able to handle an adult roof rat.

• There is no evidence that ultrasonic and electromagnetic devices drive rodents away. There is evidence that ultrasonic devices can cause hearing loss in pets, especially dogs.

• Maricopa County Vector Control tested Coca Cola (rumor has it that roof rats can’t burp and die from drinking it), but found that it was ineffective. In fact, the rats loved it.

• Don’t use d-Con. If pets or wild birds nibble on a rat killed with d-Con, they can become sick.

Long-term solutions:

• Strongly consider xeriscaping your yard. Xeriscape doesn’t have to be gravel and a couple of cactuses. There are many lovely options.

• Combine xeriscape with a citrus-free yard to create a very effective control against roof rats.

• Maintain a defensive line on your property by continuing the use of bait stations, keeping a clean yard and removing pet food and water dishes at night.