Light Snack for Ants Leaves Temple City Drivers in the Dark

The first Temple City traffic light blacked out in September. Another short-circuited in December, sparking a small, underground flash fire. A third signal went dead in January.

Neither power outages nor pranksters were responsible. Ants, munching away at the insulation on wires, were the culprits.

“People think it’s sort of a joke. It’s really not,” said Public Works Director Chris Peterson. Rewiring the three lights cost the city more than $22,000.

Familiar Phenomenon

Temple City is having its first serious taste of a phenomenon familiar to many cities and to engineers at the state Department of Transportation and the county Public Works Department.

Anaheim-based Signal Maintenance Inc. services traffic lights for about 70 cities, including Temple City, in Los Angeles and Orange counties. Operations manager Walter Cuk said almost every city has had the problem at one time or another.

Last month Peterson sent out questionnaires to 27 cities to find out how prevalent the problem is in the San Gabriel Valley and how others are handling it.

According to partial survey returns, West Covina has resorted to a wasp and hornet killer. San Dimas uses Raid. Arcadia isn’t doing anything because damage is minor. Montclair declared that nothing is effective against the ants. Monterey Park and Azusa have never had the problem.

Repairmen from the county Public Works Department, which helps 58 cities maintain their traffic signals, make the rounds of 1,200 intersections armed with cans of ant and roach killer.

“It’s just a part of routine maintenance,” said Terry Green, director of technical services for the department.

“I don’t know what kind of nutrition they get out of (eating wires),” he said.

Smells Like Food

None, according to Roy Snelling, collections manager in the county Museum of Natural History’s entomology section. Something--he has no idea what--in the plastic insulation apparently emits a smell that makes ants think it’s food.

“They find out it isn’t, but they keep on trying,” he said. “Ants aren’t terribly smart.”

Concerned that more signals might succumb to the insects in Temple City, Peterson is seeking contracts for “ant-proofing” the wiring at the city’s 27 intersections. Proposals received so far would cost the city about $150 a year per intersection, he said.

A dozen ant-ravaged wires dangle from the wall in Peterson’s office, some merely nibbled at, others stripped to the bare metal. A copper blob hangs from a cable where two bare wires crossed, short-circuited and melted.

“We hadn’t recognized this as a serious problem. We’re hoping poisoning will stop further damage,” he said, referring to the different pesticides he is experimenting with.

Peterson said he is less concerned about cables for street lights because most are above ground.

‘Ant-Resistant’ Wire

Two years ago, Caltrans created a special committee to deal with chronic blackouts, said department spokesman Thomas Knox. The group came up with an “ant-resistant” wire insulated with a different plastic. It has been used for all rewiring since last year, he said.

Pasadena is beginning to investigate alternate types of wiring. The city replaced wiring at eight intersections last year, said traffic maintenance supervisor Bob Gonzales. An aerosol pesticide was also used, but it was discontinued after six months when repairmen started becoming ill, he said.

Joe Provenza, an associate electrical engineer at Caltrans who teaches maintenance classes for the Traffic Signal Assn., said he advises using flakes of bathroom deodorizer as an ant deterrent.

Gophers occasionally chew on the insulation too, Provenza added, and lizards have been a problem in Hawaii.

Cuk of Signal Maintenance remembers a contract he undertook in the late 1950s to install traffic signals at 10 intersections on Lakewood Boulevard in Long Beach. After the three-month project for Caltrans was completed, he flipped the master switch. Nothing happened.

The curb-side cabinets containing the signal controllers were infested with dark-brown ants, Cuk said. They were so densely packed together that they blocked the electrical contacts so that the lights could not be activated. Cuk said he had to pick them out with tweezers. Underground wires were found completely stripped of insulation.

“Those damned things ate 4 1/2 miles of cable,” he said.

When he stepped on the ants, Cuk said, they seemed to spring back up and crawl off--maybe because of all the rubber insulation they’d eaten.