CHICAGO, Ill. (NBC) - Was last year's mild winter was good for Chicago's rat population. Complaints about rats are up 28 percent city-wide this year. In the 2nd ward, there almost twice as many complaints than last year at this time.
Entomologist George Manning of American Pest Solutions disagrees with the mild winter theory.
"I have difficulty accepting that. Because we have rat problems up in the northern countries," he says.
The City Department Streets and Sanitation says it's baiting rats with poison more efficiently this year, but Manning says that and other ground-level solutions like bait boxes are band-aid fixes for a problem that runs much deeper, literally.
"Rats use the sewers as a super highway, traveling. And these sewers are now over 100 years old," he points out.
Until thousands of miles of aging sewers are replaced, he says the battle against city rats is up-hill.
"If you don't follow up and repeat and come back and repeat and repeat, you're not gonna make a difference. Rat populations will build up faster than you're killing them," he explains.
The typical measures like keeping garbage secure and cleaning up after dogs help, but long-term?
Manning says communities need to work together to find the underground colonies populating entire neighborhoods, using sewer cameras.