Eric Adams — mayor, landlord and apparently a New Yorker like everyone else — has beaten a $300 ticket for a rat infestation at his rental property in Brooklyn.

The mayor, who has made his hatred of vermin a political asset, convinced a hearing officer that he had taken sufficient steps to rid his building on Lafayette Avenue in the Bedford-Stuyvesant neighborhood of pests. The case was dismissed.

On Tuesday, Mr. Adams told the hearing officer that he had spent nearly $7,000 in March trying to drive out the furry interlopers, promising that he would prove it with an invoice. He had tried several extermination tactics, he said, including the infamous “Rat Trap” that he once showed off as Brooklyn borough president — a contraption that involves luring rats into a vat and ladling out their drowned carcasses.

Mr. Adams convinced the hearing officer that employing an exterminator who could clean out burrows in foundation cracks would do the trick.

According to the officer’s ruling: Mr. Adams “placed rat traps around the property and helped educate and encourage his neighbors to take similar steps to combat infestation.”

It was unclear on Thursday evening whether the rats were gone, but the ticket was.

Mr. Adams has waged a long war with rats, one that precedes his mayoralty. When he was running for mayor, he told The New York Post that there were so many rats in his childhood home he and his siblings kept one as a pet.

As mayor, he has continued to champion innovative ways of killing the ubiquitous rodents, which have become newly bold during the pandemic. They have taken up residence in dining sheds and dined like royalty on the city’s trove of curbside trash bags.

Since Mr. Adams took office in January, the eradication of the pests has become a central element of Mr. Adams’s policy agenda.

Last week, he announced a new City Hall job: director of rodent mitigation. The job is supposed to be filled by someone with the “stamina and stagecraft” to kill a lot of rats. Also: “general badassery.”

But this week, Mr. Adams’s war on rats hit closer to home. At the hearing, it emerged, a health inspector had issued a summons to Mr. Adams on May 10 for violating the health code at the Lafayette Avenue property.

“Active rat signs exist in that fresh rat droppings were observed near the meters and near the neighboring staircase at front right,” the inspector wrote.

Haltingly, Mr. Adams took on his own City Hall. First, he failed to respond to the summons. Then, he failed to appear at a hearing.

The Office of Administrative Trials and Hearings, a tribunal that oversees rat matters, found Mr. Adams in violation of the summons by default.

At the hearing on Tuesday, Mr. Adams’s lawyer explained that the mayor did not learn about the summons until Sept. 1, because he no longer lives at the address in question, having decamped to Gracie Mansion, New York’s official mayor’s residence on the Upper East Side.

The minimum penalty was $300, the maximum was $600. It was likely affordable for the chief executive of the nation’s most populous city: He earns $258,000 a year.

At Tuesday’s hearing, he noted that city laws were “designed to penalize homeowners for failing to take steps to prevent and control rodents.”

“I took those steps,” he added, “and will continue to do so.”