ASTORIA, Ore. (AP) — Oregon's largest cities — Portland, Eugene and Salem — have been seeing an uptick in urban rats this year.

Rats have also been spotted on the streets of Astoria, but that is nothing new for the city in northwestern Oregon. Seventy years ago, Clatsop County was one of 22 places in the U.S. selected for a demonstration on how to deal with outsized rat populations.

That winter, the Astoria City Council received a letter from a county health inspector and a county sanitation officer who said Astoria needed a rat control campaign, according to newspaper reports at the time.

The city is a "seaport, accessible to rats bringing disease from abroad," they warned, and "the presence of underground passages and sewers opening on the waterfront encourage the development of a big rat population."

County officials recommended a two-fold war: Attack obvious food sources and the rats themselves. At one point, more than 10,000 rats were killed at city dump sites in Astoria and Warrenton, victims of what was described as the "deadliest rat poison ever developed."

The drama has died down over the ensuing seven decades, but the battle continues, The Daily Astorian reports.

Thousands of tiny rodent footprints dot the ground in the tunnels below downtown Astoria, and city workers bait 38 manholes each month to keep the rat population down in the sewer system.

Still, rats are the No. 1 issue that pest-control technicians deal with on the coast, followed by ants and wood-boring beetles.

Reports of a rat infestation usually begin with a frantic call, said Enrique Nieves, a technician. When he inspects a house, his first move is to figure out how rats are getting in.

"My rule of thumb is the rule of thumb," he said. "If your thumb can fit in a hole, a rat can basically squish down and fit into that hole."

One home contacts the city Public Works Department nearly every month about rat problems, said Ken Nelson, the city's public works superintendent. When there are complaints about rats in a specific area, city staff will bait the nearest manhole.

There is no way to estimate the size of Astoria's rat population. All Nelson knows is that one month, a block of rat poison at one manhole might be completely untouched. The next month, three blocks might disappear.

There are stories about people who heard splashing in their bathroom and found a rat swimming in the toilet, and county health inspectors occasionally find evidence of rats in the restaurants they inspect. But that's Astoria.

"Anywhere you've got water and harborage then there's going to be rodents," said Meredith Riley, a county environmental health inspector. "They just kind of go with the territory."


Information from: The Daily Astorian,