Wow. Could they have come up with a more complicated and expensive solution?

City officials have spent millions of dollars trying to cull the rat population over the years, deploying everything from birth control to vermin-proof rubbish bins.

On Thursday they said they had at last found a solution: a machine that attracts rats with bait and then triggers a trap door that drops them into a pool of alcohol-based liquid.

The machine – called Ekomille – is battery operated and resembles a cabinet that stand about two feet (60cm) high.

Rats climb a ladder to eat the bait. A sensor deploys a trip lever which plunges them into a tray that can hold 80 rat carcasses.