Tips to Help You Win the Rat Race
Question: Rats have been eating my avocados. What can I do to eliminate them?
J.B., Anaheim
Answer: To properly control rats, you must focus on controlling the three things that they need to thrive--food, a water source and cover.
First, eliminate food sources. Harvest ripe fruit on a regular basis and pick up fruit that has fallen on the ground.
Avoid leaving uneaten pet food where rats have access to it. Always store pet food or birdseed in a metal container with a tightfitting lid.
Because roof rats feed on snails as well as pet feces, control the snails and clean up pet droppings as soon as possible. Tightfitting trash can lids will also help to minimize access to this food source.
The next step is to eliminate their water source. Repair leaky faucets and provide adequate drainage so you don’t have any free-standing water.
And eliminate potential nesting sites and areas of shelter outside your home. Clean up all debris that might provide a suitable rat habitat. Start near your home and work outward, creating a rat-free perimeter. Keep palm trees and yuccas well-trimmed.
If you have Algerian ivy, bougainvillea, oleanders or other plants with dense foliage, thin them periodically and trim them away from roofs, walls, fences, utility poles and trees.
Orange County Vector Control suggests using the following ground covers, which are not attractive to rats, as substitutions for Algerian ivy, which is one of their favorite refuges: Bronze ajuga (Ajuga reptans atropurpurea); giant ajuga (Ajuga crispa); chamomile (Chamaemelum nobile); creeping speedwell (Veronica repens); creeping thyme (Thymus serpyllum); dichondra (Dichondra repens); germander (Teucrium chamaedrys); Hahns ivy (Hedera helix); needle point ivy; Mondo Grass; sand strawberry (Fragaria chiloensis); snow-in-summer (Cerastium tomentosum); spring cinquefoil (Potentilla verna); trailing African daisy (Osteospermum fruticosa); and woolly yarrow (Achillea tomentosa).
*
And, rat-proof your home. Remember, rats can enter your home or other area of harborage through openings of less than a half-inch by a quarter-inch in diameter. They have a 36-inch vertical leap and can jump horizontally about 48 inches. Walk around the periphery of your home and look for any possible signs of entry.
Make sure that areas around pipes and vents are properly sealed and chimneys and plumbing vents have the proper screens in place and they are secure. Inspect tile roofs around the eaves, and look for missing shingles or gaps around attic vents.
Check to see that garage doors and other entries don’t have openings at the bottom. Always leave the garage door closed at night or when not in use.
Be sure to wait until the rats have been eliminated before removing their harborage or nesting areas because this will prevent them from dispersing into the surrounding areas.
To eliminate them, use baits or traps. If you live in Orange County and feel that you have an outdoor rat problem, contact the Orange County Vector Control District at (714) 971-2421; South County residents call (800) 734-2421.
A Vector Control technician will come to your home free of charge. He or she can set bait stations if necessary and give you guidance if you choose to set your own traps. (They only deal with rats--not mice--outside the home. For a rat or mouse problem in your home, you will need to call a private pest-control company.)
Rat traps and poison baits can also be purchased at retail nurseries and many grocery, drug and hardware stores. However, keep in mind that if you use poison baits and the rats die in your house, there is a good chance the rotting carcass will smell and attract flies.
Keep in mind that for control of roof rats over the long term, trapping and chemical control alone are not sufficient. You will need to be diligent in eliminating or at least minimizing their preferred nesting sites and food sources. Proper sanitation will do a great deal to control all rodent pests.
One final suggestion: Don’t remove tall trees. Hawks and barn owls live in tall trees and are the main predators of rats. Barn owls are exceptional rat killers.
Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides answers to specific questions. You can reach the hotline at (714) 708-1646 or send e-mail to ucmastergardeners @yahoo.com. Calls and e-mail are picked up daily and are generally returned within two to three days.
