Rats in the elevators, rats in the halls. Rats in the ceiling, rats in the walls.

A rodent invasion - including the discovery Tuesday of two dead rats in file drawers - has forced dozens of New York City Human Resources Administration workers from their workplace in the Bronx.

There had been rat sightings in the building for several weeks, but Thursday, a day after the city’s Health Department exterminators put out poison, the rats seemed to become bolder, workers said.

The rodents strolled into offices in broad daylight, sending terrified workers running screaming from the building, workers said.

“I saw seven or eight scurrying on the main floor. They were rats the size of small cats, very big,” said John Owens, an Office of Employment Services worker.

Arnie Goldwag, the representative for Social Service Workers Local 371, called for a shutdown of the building.

“These rodents are acting unrodent like. They are walking around in the halls during working hours,” Goldwag said. “The city gave them cheap poison that made them psychotic. Rats don’t march up to you and maybe bite you unless their mind is shot.”

Health Department spokesman Sam Friedman denied that the city was making the rats crazy.

“We do not use any psychoactive exterminating materials. We just use the normal stuff,” Friedman said.