Chicago’s rat battle gets more money and muscle

CHICAGO -- The city of Chicago is adding five new eradication crews and replacing old and cracked garbage carts -- all of it in an effort to reduce Chicago's sizable rat population.

Chicago's rodent population is never a pretty picture, but milder winters and abundant food supplies have added challenges for Streets and Sanitation crews.

Chicago's remarkably adaptable Norway rats are difficult to corral. They have a short 6- to 12-month lifespan, but the females produce up to 7 litters in that short life. The rats have very strong teeth and are able to chew through wood and plaster. They are excellent climbers and swimmers, able to tread water for days. They can crawl through holes the size of a quarter, and land unharmed after 5-story falls.

With cold weather upon us, the rats are looking to come indoors.

Orkin Pest Control recently named Chicago as the American city with the largest rat population. The Department of Streets and Sanitation says there is no reliable and scientific way to estimate the city's rat population.