A coyote photographed by a motion-activated camera along the Los Angeles River. (National Park Service)

Courtesy of the Wildlife Center of Silicon Valley

A young coyote, one of five orphaned when their mother was struck and killed, is being cared for by Wildlife Center of Silicon Valley. (Courtesy of the Wildlife Center of Silicon Valley)

(12-10-99)--JOSHUA TREE NATIONAL MONUMENT--A coyote looks in at a driver who pulled off the road inside Joshua Tree National Monument. Coyotes in the park are becoming seeking handouts from drivers passing through. PHOTO BY DAVID CREAMER. Actual: 12-28-1999---A coyote looks in at a driver who pulled off the road inside Joshua Tree National Monument.

Juvenile coyotes run around in a pen at the Wildlife Center of Silicon Valley on Thursday, July 6, 2017, in San Jose, Calif. (Jim Gensheimer/Bay Area News Group)

BRUCE CHAMBERS/ORANGE COUNTY REGISTER

How do coyotes thrive in Southern California? Scientists dissect 200-plus carcasses to find clues ( BRUCE CHAMBERS, THE ORANGE COUNTY REGISTER)

Courtesy of Wildlife Center of Silicon Valley

When a coyote was killed in a hit-and-run accident in San Jose, she left behind five pups believed to be about 6 weeks old. They will be cared for until fall, when they should be ready to be released on their own. (Courtesy of Wildlife Center of Silicon Valley)

A family of coyotes can often be seeing basking in the sun, or playing on the hillside behind Monte Deignan's Larkspur home. Deignan, a city planning commissioner, said seeing the coyotes has helped him and his neighbors understand that the community can coexist with the wild animals. Larkspur city officials along with their Corte Madera neighbors are hosting an informational meeting on Monday with officials from Project Coyote, the Marin Humane Society and Marin County Parks, who will offer tips on coexisting with the animals. The meeting is at 6:30 p.m. on Monday, Dec. 12 at Corte Madera Town Hall at 300 Tamalpais Drive. (Photos by Monte Deignan)

A family of coyotes can often be seeing basking in the sun, or playing on the hillside behind Monte Deignan's Larkspur home. Deignan, a city planning commissioner, said seeing the coyotes has helped him and his neighbors understand that the community can coexist with the wild animals. Larkspur city officials along with their Corte Madera neighbors are hosting an informational meeting on Monday with officials from Project Coyote, the Marin Humane Society and Marin County Parks, who will offer tips on coexisting with the animals. The meeting is at 6:30 p.m. on Monday, Dec. 12 at Corte Madera Town Hall at 300 Tamalpais Drive. (Photos by Monte Deignan)

A family of coyotes can often be seeing basking in the sun, or playing on the hillside behind Monte Deignan's Larkspur home. Deignan, a city planning commissioner, said seeing the coyotes has helped him and his neighbors understand that the community can coexist with the wild animals. Larkspur city officials along with their Corte Madera neighbors are hosting an informational meeting on Monday with officials from Project Coyote, the Marin Humane Society and Marin County Parks, who will offer tips on coexisting with the animals. The meeting is at 6:30 p.m. on Monday, Dec. 12 at Corte Madera Town Hall at 300 Tamalpais Drive. (Photos by Monte Deignan)

Vern Fisher/Monterey Herald archives

A coyote on the Whisler-Wilson Ranch south of Carmel. There have been numerous sightings of coyotes in Monterey County lately. Vern Fisher - Monterey Herald file

Karen Nichols/Daily Inter Lake

FILE - In this Feb. 10, 2013, file photo, A coyote stands in a field in this undated file photo. Hunters are tromping through the countryside of a remote Northern California county, as they compete in a controversial contest to see who can kill the most coyotes. Organized coyote hunts that award prizes to the top marksman have sparked a culture clash in California between wildlife advocates who value the animals as an essential part of the landscape and people who view coyotes as wily varmints to be hunted down to protect livestock. On Wednesday, Dec, 3, 2014, the California Fish and Game Commission will consider banning prize hunts for coyotes as well as foxes and bobcats, which also are legal to kill year-round in unlimited numbers. (AP Photo/Daily Inter Lake, Karen Nichols, File)

A coyote pauses for a moment in the sun along Golf Club Drive in Pogonip. (Shmuel Thaler Santa Cruz Sentinel file)

A coyote saunters along Modesto Avenue on Santa Cruz's Westside. (Dan Coyro -- Santaa Cruz Sentinel)

Bay Area News Group archives

Coyotes have moved into developed areas and show signs of going away.

New York City Police Department Special Operations Division

In this photo provided by the New York City Police Department?s Special Operations Division, a female coyote lay in an animal carrier after being captured by Special Operations officers on Manhattan?s west side, Saturday, April 25, 2015, in New York. The police released the coyote to the custody of the American Society for Prevention of Cruelty to Animals, where she is being cared for. A string of recent sightings in Manhattan has drawn new attention to the wily critters that have been spotted periodically in New York since the 1990s.(New York City Police Department Special Operations Division via AP)

Coyotes are becoming common in urban areas. (Courtesy of John Shilling)

e, Debra Hamilton/California Department of Fish and Game

Coyotes removed from an urban area from the California Department of Fish and Game. (California Department of Fish and Game, Debra Hamilton)

In this photo taken Sunday, Sept. 11, 2011, one of the coyotes that has moved into a burned-out Southern California house is seen in Glendale, Calif. Two adults and several pups are believed to be living in a burned-out house. The owners have given Los Angeles County permission to set traps on their property. (AP Photo/Gary Naeve)

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DEAR JOAN: We’re having a terrible problem with coyotes. My sister wants to try some kind of ultrasonic device to drive them away. She already has bought a small device to drive away fleas from a cat that lived here.

I believe these devices are a total waste of money with no legitimacy greater than homeopathic medicine or astrology. What is your view?

DEAR MARK: I wasn’t sure whether to answer your question, but my horoscope today said it was OK to tackle controversial matters.

That’s a joke, but today is a good day to talk about ultrasonic critter ridders. There is some evidence that they work, and a lot of evidence that they don’t.

Many factors come into play, including what type of device you get. For the most part, ultrasonic waves emitted from these devices are weak and can be easily blocked by buildings, hills, trees, shrubs and Cousin Eddy sitting on the porch whittling. There are even more issues when used inside as an insect repellent.

Animals also become accustomed to the sounds, so while they might annoy the coyotes for a bit, the deterrent doesn’t have staying power.

There are devices, however, that have a better track record. Products that flash red lights to mimic the eyes of a predator have a high success rate. So does playing a CD with sounds of mountain lions, the coyotes’ biggest threat. Devices that emit random sounds at different frequencies also have gotten good reports.

Installing roller bars on the top of your fence also will keep coyotes out of your yard. You also can use motion-activated lights and sprinklers.

Any deterrent you choose will have better results if you take steps to make your yard less attractive to coyotes.

DEAR JOAN: I thought I would add something to your response as to why the Siamese cat suddenly attacked her brother when he returned from the vet.

Every time either one of our cats went to the vet, the cat that remained at home did not recognize the other one when we came back.

Related Articles Young California girl, puppy bonded over their mutual deafness, grew up together in mutual love Bay Area rescue group buys van to perform spay-neuter surgeries on cats Will Western screech owl make its home in my yard? Pets of the Week: Sunny and Bucky Readers share their stories about cats providing comfort and care when needed We started cleaning the carrier with soap and water and washing the towel in the bottom after every visit. We also removed those vet smells (fear) by wiping down the cat that was coming back from the vet with a shirt from my husband or me. This immediately stopped the problem.

DEAR MARY: Brilliant solution. Thanks for sharing.

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