The number of Chicagoans calling the city to complain about rats is up 28 percent, according to a Chicago Tribune report.
Since July, the city's 311 center has received almost 15,900 calls from residents, compared to the 12,000 over the same period last year. Residents can also file rat complaints online at cityofchicago.org and request city crews visit properties that provide conditions susceptible to rats. Crews can then issue "rat stoppage tickets" to owners.
The report cites the warm winter as one of the reasons for the increase in the rat population. Rats have to forage for food, and when the temperatures are mild, that's easier. The City of Chicago website indicates rats find most of their food in alleys and encourages residents to make sure trash is placed in containers that are properly closed.
"Remember if rats can't feed, they can't breed!" the cityofchicago.org website reads.
Residents are also encouraged to call 311 or enter complaints online. According to the city's website, "Chicago's Bureau of Rodent Control investigates every reported rat sighting" and poison is placed in rat nests.
The species of rats found in Chicago is the Norway rat, which have an average life span of six to 12 months. The females can have up to seven litters of 12 pups a year.
While they prefer fresh food, the Norway rat will eat garbage, pet food, dog feces, and even its own young. These rodents live in colonies, and, according to the city website, "They can crawl through holes the size of a quarter, tread water for three days and land unharmed after a five-story fall."