And now, rats: US disease control centre issues aggressive rodent warning

Humans aren't the only ones hankering for the days they could dine out at their cities' restaurants: the US Centres for Disease Control and Prevention warns that rats are becoming increasingly brazen in their hunt to find new food sources.

Amid stay-home restrictions set across the US to battle the spread of coronavirus, many restaurants and cafes are closed or limited to take-out and delivery, and with the reduced sales, the restaurants' rubbish bins are no longer overflowing with those leftovers on which hordes of rodents feasted. Finding slimmer pickings than they used to, rats are more aggressive, prompting the centre to issue guidance on how to deter them.

Since the start of the pandemic, there have been increased reports of rat cannibalism and infanticide in New York, as well as more rat complaints in residential areas — including in Chicago — as humans produce more food waste at home. Roving rat armies, including one caught on camera scavenging New Orleans' empty streets, are worrying the CDC, which says rodents can carry disease.

Home and business owners have been advised to cover garbage cans, put bird and pet food out of reach and seal small holes rodents could use to invade buildings. If people follow established cleaning guidelines, the agency says they can avoid exposure to rodent-borne diseases.

"Some jurisdictions have reported an increase in rodent activity as rodents search for new sources of food," the CDC said. "Environmental health and rodent control programs may see an increase in service requests related to rodents and reports of unusual or aggressive rodent behaviour."

In areas trying to combat rodents, such as the District of Columbia, pest control workers are classified as essential. The District has had more than 800 calls regarding rodents in the past month, according to city 311 data.

Rats can transmit food-borne illnesses such as salmonella and their urine can also worsen allergies and asthma, especially in children, according to Jim Fredericks, chief entomologist at the National Pest Management Association.

Rats pose an additional threat to those working from home: devouring cars. Rats gnawing at car engines and tyres have caused fires, cost car owners fortunes and goaded officials to seek DIY solutions.

Urban rodentologist Bobby Corrigan predicted increased reports of aggressive rodents when the pandemic began. He said with restaurants closing, rats would need to adapt to find new food sources. In late March, he put out a call to other pest experts to share what they found in their areas.

Corrigan said that a pest expert sent him a photo after a gruesome rat battle in Queens, New York: a nest of rats had left to scrounge for food at their usual city block of restaurants but turned on each other when they couldn't find enough scraps. A pile of rat limbs on the footpath was all that remained.

"Many of these rats in our cities depend on their nightly food, which is the restaurants and hotels and bars and doughnut shops and everything that we consume on the go," said Corrigan.

Corrigan said rats were "opportunistic foragers", so as many rats' reliable sources of food vanished, the rodents were seeking new menu options. To keep rats from dining at your home, he advised following CDC guidance, securing food properly so rats couldn't get to it, adding that he recommended people avoid inhumane traps or poison.

"Deny them the opportunity, and you'll never even know they've visited your property," he said.

The Washington Post