On a frigid Sunday morning as a rookie reporter in New York City, I was assigned to cover the launch of what was billed as a major city offensive against its rampaging rat population.

Officials estimated that the Big Apple probably had more rat residents than the 8.6 million human ones. Such certainty comes only with the knowledge that no one else is counting.

Who do you think gets the fastest municipal attention on rodent complaints? I followed city workers down the gardened median of posh Park Avenue, where high-rent payers had been complaining about numerous rodents scurrying across sidewalks in the path of wealthy pedestrians.

It wasn’t a very dramatic scene, which is why editors had sent a nobody rookie. My newspaper’s photographer had a difficult time capturing much of interest — gloved city workers shoving packets of poisoned bait down many rat holes amid the plants awaiting spring.

The city administration of Mayor John Lindsay wanted publicity to show its responsiveness to the voices of  citizens. This street-level offensive was said to be but the first of many assaults across the 305-square miles of the nation’s most populous city. The goal being to eradicate these infernal infestations of rodents once and for all. The rat offensive story nearly made Page One of the New York Times that night.

Oh, I should tell you that Sunday morning was in  — wait for it — March of 1969.

Apparently, that Great Park Avenue Plot didn’t work out so well, as many government photo-ops don’t.

Fast forward 2,562 weeks to New York the other day with a different mayor, Bill De Blasio, also full of unfulfillable promises. He should consider ducking future photo-ops involving animals.

You no doubt remember Groundhog Day four years ago when the same mayor went all the way to Staten Island to don thick gloves and hold up Staten Island Chuck for the annual phony weather forecast on the evening news.

Alas, Chuck turned out to be a Charlotte. And the six-foot-five mayor dropped her.

The innocent creature was found dead in her zoo cell later, the victim of massive internal injuries.

This week De Blasio popped up in another borough, Brooklyn, to demonstrate for more cameras the Housing Authority’s amazing new plan to murder rats, but to do so with a heart.

Problem is, rats are clever creatures. There’s a reason the wily, filthy rodents have survived for millennia to travel the world on trading ships and deliver the plague to Europe and so many other dastardly deeds.

Until now in Gotham, poison has been the preferred instrument of execution because — shh, don’t tell them — rats’ weakness is their inability to vomit. So, once they munch on a tasty wax bar or pellets laced with poison, it’s curtains. Trouble is, in nature’s food chain anything else that dines on poisoned rats also gets poisoned

De Blasio is a progressive Democrat of the humane species who believes government can fix these problems. He was a seven-year-old boy during that earlier rat offensive.

De Blasio was eager to showcase the Housing Authority’s new plan to rid his city of rats: To stuff dry ice down rat holes, block the exits and let the creepy critters suffocate in the cold. “Once you put that dry ice in there,” the mayor proclaimed, “rats are not going to live through it.”

Uh-huh.

Cameras ready?

Dry ice goes in the hole.

Pause.

Shifty rat exits another hole.

He scoots all around, showing off for cameras. City workers chase him (or her) here and there. And back to here. Then, again over there. One bully even swings a shovel. Clang! He misses.

Rat jaywalks across Humboldt Street to a nearby playground.

Mayor De Blasio is never at a loss for words, even when he’s skunked by a rat. He told reporters he was giving city workers “an A for effort.”

As with so many of his ancestors, the rat doing the little end-zone dance across the street gave them an F.