Gangs of hungry, violent rats take over US cities’ streets

NEW YORK: Humans aren't the only ones whose lives have been disrupted by the coronavirus pandemic. Millions of rats that live below the streets of big US cities have seen their world turned upside down—and the results can be violent.

When times are good, the rats inhabit subways, sewers and basements by day. They emerge mainly at night to feast on the considerable amount of food left over from restaurants – an estimated 22 billion to 33 billion pounds of food waste each year in the US.

In a city like New York, which had about 27,000 restaurants as of 2018, that amounts to a considerable supply of food—enough to support about two million rats, the third largest rat population in the US after Chicago and Los Angeles, reported foreign media.

The March lockdown caused a major disruption in the food supply-chain for rats. No longer were restaurants tossing half-eaten hamburgers, pizza slices and sushi to the sidewalk in thin, plastic garbage bags that rats easily penetrate with incisors that have been known to gnaw through metal, concrete and brick.

For the past months, these normally cloistered creatures have been taking to the streets in broad daylight—behaviour that has astonished rat experts. "We didn't realize they were so dependent on our garbage for survival," says Bobby Corrigan, an urban rodentologist and pest management consultant who designed rodent control programmes for New York City's Department of Health and Mental Hygiene. "The pandemic proved just how dependent they are on us."

In Chicago, packs of rats that don't normally travel more than 150 feet outside their burrows are venturing further to look for their next meal. In New Orleans, rats have been spotted scurrying out into the open and empty streets frantically searching for food. Midtown Manhattan, an area of New York City normally bustling with humans, is now occupied by armies of desperate rats, who run free digging through garbage bags. In May, the Centers for Disease Control and Prevention warned that rats were becoming increasingly aggressive in their hunt for food, as restaurants across the US remain closed.

Rats generally live in packs of a dozen or so, led by an alpha rat that is bigger, stronger and faster than the followers. Each pack establishes territorial foraging habits that usually keep conflict to a minimum. Now that rat packs are searching far and wide for new sources of food, however, they've clashed frequently, and often violently, resorting to cannibalism and infanticide and littering the streets with dismembered corpses.

The bright side of the rat wars is that humans are not among the casualties: rats are only aggressive and violent only toward each other. "They won't come fighting our ankles or trying to attack us when we sleep," says Corrigan.