Forget The Murder Hornets. Beware The Cannibal Rats.

First there was the coronavirus. Then came “murder” hornets. And now here come the cannibal rats.

With major cities becoming ghost towns amid fears of COVID-19, rat populations are surging. But with restaurants closed and city garbage cans mostly empty, some rats are turning to eating … each other.

The Centers for Disease Control and Prevention (CDC) recently put out a warning about “unusual or aggressive” behavior in rats.

“Jurisdictions have closed or limited service at restaurants and other commercial establishments to help limit the spread of COVID-19. Rodents rely on the food and waste generated by these establishments. Community-wide closures have led to a decrease in food available to rodents, especially in dense commercial areas. Some jurisdictions have reported an increase in rodent activity as rodents search for new sources of food. Environmental health and rodent control programs may see an increase in service requests related to rodents and reports of unusual or aggressive rodent behavior,” the CDC said.

The U.S. health agency also said rats have been observed resorting to eating their young in the wake of urban shutdowns.

“The rats are not becoming aggressive toward people, but toward each other,” Bobby Corrigan, an urban rodentologist, told The New York Times on Sunday. “They’re simply turning on each other.”

“They are going to war with each other, eating each other’s young in some populations and battling each other for the food they can find,” Corrigan said. “But the rats that live and eat in residential blocks probably haven’t noticed a single bit of difference during the shutdown.”

In case you haven’t heard, Asian giant hornets, or, more scientifically, Vespa mandarinia — but also known as “murder hornets” — have arrived in America.

“It’s a shockingly large hornet,” Todd Murray, a specialist in invasive species at Washington State University (WSU), told CBS News, which added “while generally not aggressive towards people or pets, the hornets can attack if provoked, officials say, and have killed humans in extreme circumstances.”

The two-inch-long hornets started showing up in Washington state in December, and there are fears that the insects will spread across the country. The hornets kill upwards of 50 people in China and Japan each year, and they also attack honeybees, which pollinate the fruits and vegetables we eat.

Scientists fear the hornets, like the stink bugs that emerged in the U.S. several years ago, will eventually sweep the nation.

Meanwhile, wild animals are reportedly roving all over the country amid the empty cities and locked down suburbs.

“Animals have started taking advantage of cities as they enter lockdown during the coronavirus pandemic. From New Delhi, India, to Buenos Aires, Argentina, groups of animals including deer and lemurs have started to come out to explore — in search of food or just to play,” The Guardian wrote.

“Pigs Are Taking Over the Streets of Paris,” said another headline.