Stand clear of the bloodsucking parasites!

Bedbugs were discovered on at least three subway trains on the N line this week, authorities said.

Two trains were taken out of service Sunday after the unwanted riders were found onboard some cars, officials said. And on Tuesday, a third N train was also sent to the Coney Island yard in Brooklyn for fumigation. Some of the bugs were found in seat cushions in train cabs, which are used by conductors and motormen, sources said.

Carolyn Kaster/AP Some of the bugs were found in seat cushions in train cabs, which are used by conductors and motormen, sources said.

"When we found them, we exterminated them," said Metropolitan Transportation Authority spokesman Adam Lisberg.