As restaurants are reopening to allow outdoor seating in New York City, rats are returning to feast on the trash they leave behind, causing experts to expect a rise in rat attacks on outdoor diners.

NYC Rats, Restaurants, CoronavirusSean Gallup / Getty Images

Urban rodentologist Dr. Bobby Corrigan says he's seen drastic changes in rodent behavior in his own condominium: “You wouldn't believe what’s going on outside my condominium, it’s kind of crazy I hear screaming rats down in the street,” Corrigan told Gothamist.

He says friends have been calling him to warn him about the rats. He described one call saying, “'I’m watching rats, I never seen them play in the park before, they’re wrestling, they’re playing it looks like they’re happy.’ I said, trust me, they’re not playing, somebody is going to be killed shortly and eaten!”

"Any mammals, if you take the food away you’re going to have abnormal behavior show up really quick," Corrigan said.

New Yorker Elias Schewel told NY1 that he takes his dog out rat hunting. “We are not providing a service,” Schewel says. “We are doing it for fun.”

"It’s actually been a great pleasure of mine watching [Sundrop] learn how to make a kill," Schewel continued. "It’s like whack-a-mole."