The closure of restaurants and the retreat by humans indoors is having an effect on the eating habits and behaviour of rats.

One of the New York-based consultant to many health departments and other agencies across the country, including in Baltimore, experts on rodents Robert Corrigan has a warning amid the coronavirus outbreak. You could see more rats on streets because of COVID-19. Robert Corrigan, PhD is an expert in the science of rodents. He says, “Rats and diseases go way back.”

In New Orleans’s storied French Quarter, the tourists and their trash are gone. Suddenly hungry rats are venturing forth during the day in large numbers. In Seattle, rats have been seen wrestling in public parks in the afternoon.

Not long after the coronavirus closed bars and restaurants in the Louisiana city, rats were coming out of hiding.

Photo: Hungry rats in city streets during the pandemic

Humans around the world are changing their behaviours due to the threat of the coronavirus pandemic. In some places, quarantine means rubbish that rats depend on is no longer available, and so they also adapt.

If there is food available, pest populations could thrive in empty buildings and become emboldened by the absence of people - or pests will go out in search of food.

They are "formidable mammals" very good at sniffing out sources of food, and their powerful teeth can make short work of a barriers like doors, plastics, or fabrics.

Rats are "officially associated with about 55 different pathogens", though there have been no reports of rats carrying Covid-19.