LAURA SIMON, field director for the Humane Society’s Urban Wildlife Program, does not mince words: “People are repulsed by their appearance.”

Can you blame them? Opossums, after all, do look like bloated rats — the scruffy fur, the flinty eyes, the bizarre little feet and long, scaly tail. And that’s their good side. Threaten one of them, and it will bare its teeth, hiss and drool.

But as disgusting as the animals may appear, they actually do quite lovely work in the garden. Opossums are nature’s clean-up crew, working the graveyard shift. Like little dust busters, they cruise the landscape, round ears tilted like satellite dishes, fleshy pink snoots to the ground. They feast on snails and slugs, perhaps even a cockroach or two.

Gardeners may blame opossums for the messes and mischief made by rambunctious raccoons, skunks and squirrels rooting out insect grubs, but the reality is that opossums don’t dig. They can’t. The soft pink skin on their paws is too delicate for such manual labor; their weak nails are built for tree-climbing.

Though opossums are excellent at scaling trunks, they rarely sample the fruit above. Instead, they might salvage a fallen peach or munch avocados knocked down by squirrels. Opossums prefer their produce at ground level and well rotted — all the easier to sniff out as they forage the night garden.

The animals are effective scavengers, says Jim Dines, collections manager of mammalogy at the Natural History Museum of Los Angeles County. It may not help their image problem, but opossums do eat the really gross stuff too: stinky carrion that other wildlife simply won’t consider. Lest you get too disgusted, just remember that this is the detritus that no gardener wants to handle, even with gloved hands.

IF opossums are so docile, harmless and downright helpful, then why are so many people — even sensitive gardeners who have designed their landscapes to attract wildlife — so intensely repulsed by this animal?

The average person thinks they’re so ugly, they’re scary, says Simon of the Urban Wildlife Program. Most calls coming into the hotline that she runs are fear-based.

“People think the animals must be rabid,” she says.

In truth, Simon and other experts say, the opossum is one of the gentlest animals out there. When it senses danger, it usually just freezes, motionless, and waits for the hazard to pass.

When threatened, the animal can look awfully mean, but it’s all a big show. Opossums don’t run or bite well. They’re not very coordinated and, in Simon’s words, they’re not the most intellectual of creatures.

If the baring-teeth-and-hissing drama doesn’t work, they feign death by entering a temporary coma. This strategy doesn’t fool dogs and other large predators, according to Mary Cummins, a Los Angeles-based licensed wildlife rehabilitator and educator. She takes in 600 injured or orphaned opossums each year.

The rabies fear is unfounded because the disease is rarely found in opossums, says Catherine Conlon, a veterinarian and rabies specialist formerly with the Centers for Disease Control and Prevention and recently named director of the rabies lab at Kansas State University.

This apparent resistance to rabies may be attributed to the opossum’s low body temperature, which prevents buildup of the rabies virus. That same low body temperature may allow opossums to eat horribly decayed food without getting sick.

Rabies may not be an issue, but opossums do harbor parasites, including fleas, and they can host a bacterial disease called leptospirosis that can be transmitted to humans. That’s why it’s not smart to touch a wild opossum or keep one as a pet. Says Dines, “It’s not an animal you’d want to play with.”

THE species that calls Southern California home is actually the Virginia opossum (Didelphis virginiana), the only marsupial living in the wilds of North America. As with the kangaroo, koala and other marsupials, the female opossum nurtures her undeveloped pups in a pouch. (“Possums,” for the record, are distant relatives found only in Australia.)

The Virginia opossum is native to the Southeast, where it is still common. It emigrated west, Dines says, most likely with the help of humans, who carried the animals as curiosities or pets. The first opossum was trapped and recorded in Los Angeles County in 1906. Today, they populate wide-ranging habitats from Baja California to British Columbia.

Life in the city is grueling for the opossum. Mortality is high, and few live to their first birthday. Dogs and cars are the biggest threats. Garden pesticides, especially snail baits, also put the opossum at risk.

What to do if you see one in your yard? The opossum’s defenders will suggest that you enjoy it — perhaps smile at its prehensile tail, or note how the rear feet have evolved with nifty opposable thumbs. Admire its adaptability, then let it proceed with the good work it came to do.

home@latimes.com

(INFOBOX BELOW)

How to help the injured

If you find an injured or orphaned opossum, get help immediately. The website of the Opossum Society of the United States (www.opossumsocietyus.org) maintains a list of trained, licensed wildlife rehabilitators. The site also provides interesting background information on the animal.

— Lili Singer