REGIONAL REPORT : Driven to Drink : Thirsty Ants Invading Homes in This 5th Year of Drought

Southern California’s fifth consecutive year of drought has brought with it some creepy and uninvited guests: droves of thirsty ants have invaded homes and other buildings throughout the Southland in disturbing numbers this winter, say entomologists and pest control experts.

At a Santa Barbara blood bank last month, the packaged cookies usually offered to donors were covered with ants--a 1-inch-wide column of scavenging six-legged creatures that resembled rush-hour on the 405 Freeway.

A panicked San Diego woman offered an exterminator $1,000 for a New Year’s Eve house call, promising that if he didn’t come, she would go insane from ants.

And in Orange County, an army of invading ants, scurrying up the outside walls, recently took up residence on the eighth floor of a posh hotel, crawling on pillows and massing along bathroom fixtures.

Throughout the Southland, the lack of water has dried up the insects’ normal outdoor watering holes, prompting a relentless march of foraging ants--hurrying along floorboards and through ceiling cracks, trailing along electrical lines and leaky kitchen pipes, searching for a drink, experts say.

The drought also has depleted the normal food supply of seeds and insect larvae, forcing ants out of the garden and into the kitchen as they instinctively trade mealy bugs for marshmallows.

Making matters worse, a December cold snap drove still more shivering ants into insulated walls and beneath concrete home foundations, seeking a cozy place to sleep.

Public health officials say the ants aren’t known to carry diseases. In fact, the acid they secrete might even kill some household bacterias.

The most common ant variety in Southern California--the Iridomyrmex humilis , or Argentine ant--is not known to cause any structural damage, though they may nibble away at the wallets of anxious homeowners spending hundreds of thousands of dollars to eliminate the pest.

Mostly, Argentine ants pose more of a nuisance than a threat, experts say.

And the current season has been the worst in recent years. For Iridomyrmex humilis , this has truly been the winter of its discontent.

“Our people in Southern California are calling this just an unbelievable winter for foraging ants,” said John T. Munro of the Pest Control Operators of California, a trade group that represents 900 exterminators statewide. “They’re almost everywhere.”

Added Larry Musgrove, a Santa Barbara pest control operator: “The ant numbers are really up compared to a normal year. A 40% jump in any target pest is really an incredible jump.”

Northern California also has had its share of ant headaches, especially during the winter holidays. But overall, it is Southern California that is really getting antsy, because the effects of the drought are compounded by the normal desert-like climate here.

Herb Field, the San Diego entomologist for Lloyd’s Pest Control, said the Argentine ant has replaced the cat flea as Southern California’s No. 1 household pest.

“Fleas used to outnumber ants 5 to 1,” he said. “Now it’s 15 to 1 in the other direction. You usually don’t see such dramatic shifts in insects. And the drought definitely has something to do with it.”

For yet another year, entomologists say, the fall and winter rainstorms that would have washed away thousands of ants never came. So the colonies have thrived.

Hungry and thirsty, the usually dormant ants have crossed the threshold from picnic party-crasher to household pest in recent months, extending their usual summertime fling into a full-fledged wintertime headache.

Water plays a key role in the survival of all kinds of insects thriving in the Southland, including cockroaches, earwigs, crickets and centipedes, entomologists say.

But where the numbers of other such creatures will drop off considerably during dry seasons, the hardy, enterprising ant is much more drought resistant.

And unless the ant-cleansing rains come soon, the coming summer could be an even worse nightmare for Southland residents.

“It’s definitely going to get worse,” said Dr. Tom Atkinson, an urban entomologist at UC Riverside. “As the drought progresses, those hard-to-find food sources outside will continue to dry up.”

Meanwhile, some hardware and home improvement stores report a brisk business in ant traps, poison and other implements of insect death. Most of the complaints involve Argentine ants, but other species have been on the rise as well.

“There’s definitely a problem,” said Lorenzo Ormord, a manager at an Oceanside Home Depot store in North San Diego County. “We just got an in-house memo warning us to stock up on . . . home pesticides.”

Southland pest control operators also say business is booming. One San Diego exterminator said ant-inspired house calls helped make last year his most profitable since 1978 and that the current year is on a record pace.

“Our business is certainly up due to the ants,” said Herb Pencille, owner of Hydrex Pest Control in North Hollywood. “But overall, we’re down due to the economy.”

Many areas seem to have been hit harder than others, with some pest control operators in Orange, Riverside and Los Angeles counties saying that most of the winter has been unremarkable in terms of their overall business.

Entomologists say the infestations could be worse in high-growth areas as bulldozers disturb the soil in and around canyons, further robbing the ants of available food sources.

“Documenting the periodic outbursts of insects and where they occur is really hard,” said Rosser Garrison, entomologist for Los Angeles County, who has ant problems in his bathroom. “But certainly climate, humidity, moisture and available food and plant life all play a role.”

As a result, ants have turned up in the strangest places throughout Southland homes, pest control operators say.

They’ve crawled out of light sockets, emerged from instant coffee cans. Some Southland freezers have even become a tomb for freeze-dried ants. And the insects have covered the dashboards of cars in search of a discarded soda can.

Entomologists say the best way to get rid of ants is to douse the nest with boiling water. Also, keep kitchen counters free of food scraps and occasionally wipe counters with an alcohol-soaked rag to destroy any scents left by scouts. And keep bushes and brush pruned away from the side of the house.

But considering ants’ resilience, don’t be too surprised if the efforts don’t lead to immediate victory.

David Kellum, a San Diego County entomologist, says he has a lot of respect for the resourcefulness of the ant.

“They’ve survived for millions of years,” he said.