Manhattan's multi-legged garbage service

It may be dimensionally challenged, but the pavement ant plays a big part in stopping rats from taking over the streets of Manhattan. Insects tidy up in all the places where New Yorkers leave or drop their garbage, leaving less for bigger pests - a process examined in a recent scientific study.

Ants eat the city clean. "It's a true service; they provide effective garbage collection," says a scientist from North Carolina State University (NCSU) in Raleigh. She has investigated the phenomenon by leaving different kinds of food waste in parks and streets around Manhattan to see who devoured what the fastest.

But it's not just ants: all kinds of other creepy-crawlies including spiders and even the lowly cockroach help out. They seem to like the warm, dry streets, particularly one well-protected place ...

... the median strip. The little creatures eat up almost 1,000 kg (2,200 pounds) of food garbage per year on the green traffic islands of the famous Broadway (far left) and busy West Street alone, scientists say. That's the equivalent of some 60,000 hot dogs, according to researchers.

The bugs go where the food is. Many - particularly the pavement ants - seem to leave big green areas like Central Park to take up abode in the streets. Researchers say that this species of ant makes sure that twice to three times the amount of food garbage is cleared away in places where they are at work than in others.

Vertebrates and bugs compete for this food supply. And rats end up the losers. This is good news for New Yorkers because it means the rodents can't carry as many diseases to humans. Researchers at NCSU are therefore urging New York authorities to make the city's green spaces as ant-friendly as possible.

Pigeons, squirrels, raccoons: they all literally want a piece of the cake, even in big cities. Most food that is thrown away ends up in the bellies of larger animals. Pigeons, for example, simply have better reconnaissance options. But insects also make a very good showing. They'll go for leftovers like hot dogs, but research indicates that they prefer cookies and chips.

New Yorkers still seem to be throwing away enough food away to keep millions of insects, rats and pigeons happy. The municipal garbage service collects more than 11,000 tons of garbage every day. And that's not including all the garbage that doesn't end up in bags.