The mild winter was good to Chicagoans and to Chicago rats.
City Hall received a 28 percent increase in calls this year about the scurrying scavengers, according to the Chicago Tribune. The 311 center logged about 15,900 calls, up from last year's 12,000, the paper reports.
An urban ecology expert from the Peggy Notebaert Nature Museum blames the area's warm, blizzard-free winter on the larger rat population in city alleys and streets.
Steve Sullivan told the Tribune that because rats don't hibernate, they forage for food all year. The lack of a typical mid-winter deep freeze kept them thriving instead of dying, he said.
The biggest increase in rat calls reportedly came from the city's 2nd Ward and the South Loop, and the most poison was put down in the 35th Ward, which includes Logan Square neighborhood.
Rats aren't a new problem for Chicago. Union officials early last year said cuts in local forestry and rodent control services could leave the city with a rat problem in the summer. Then-Mayor Richard Daley downplayed the outcome and rats didn't take over.
But as is Chicago tradition, there's always next year.
To curb the issue Streets and San Commissioner Tom Byrne said he deployed 15 crews of two workers six days a week. Byrne urges residents to cover garbage cans, pick up dog feces and never leave food outside. Rats, he said, feed on it all.