It's just before daybreak in Richmond on the southern bank of the River Thames, and pest controller Michael Coates is patrolling the rubbish bins for what is normally an elusive enemy -- rats.

"There'll be something in there for sure," he says, kicking an overflowing waste container. "Rats are like little survival machines; wherever you get reliable access to food waste, they'll keep coming back."

Coates' prey has become more conspicuous in London the longer England's lockdown lasts.