The CTA said it will launch a new weapon in the war on rats next year.
In addition to poisonous traps the CTA uses to kill rats, the agency plans to test new technology that would make female and male rats infertile. A pilot program is expected to start in the spring, though the CTA is still working out details including negotiating the price with the bait maker and deciding where the traps will be placed, CTA spokeswoman Tammy Chase said.
Chase said rats "are not a notable or systemic issue" on the CTA but the agency is trying to be proactive in combating them. The CTA "very infrequently" receives rat complaints from riders, though the agency has no idea how many rodents have been spotted on CTA property because they don't count them, Chase said.
A few rats were discovered during the renovation of the Damen Blue Line stop in Wicker Park that ended Monday, Chase said. The rodents had found homes in the flooring of the station, which dates back to 1895. The CTA replaced the Damen wood floor with granite as part of its $13.6 million facelift.
"[The pilot] is definitely not a reactive thing," Chase said. "It is about the health and safety of our employees and our customers."
Brown Norway rats, the most common rat species in Chicago, can carry infected fleas and ticks that may be passed on to humans, according to the city. Rats also can bite humans or pets. City spokesmen did not return a request for comment on the size of Chicago's rat population, though pest control company Orkin named Chicago America's "Rattiest City" in October based on the number of rodent treatments the company performed last year.
The new bait the CTA plans to test in the spring is called ContraPest, made by Arizona company SenesTech, which tested the traps in the New York subway last year. The bait, which comes in semi-solid or liquid form, is placed in a small box for rats to eat so they have a more difficult time reproducing.
Female rats lose eggs while male rats have testicle problems, according to the SenesTech Web site.
After the rats eat the bait multiple times, they typically make fewer babies within four weeks, according to SenesTech. Full sterility usually occurs within eight to 12 weeks. SenesTech says the bait doesn't kill the rats or poison them, and it doesn't harm humans or the environment. SenesTech did not return multiple requests for comment.
SenesTech traps were placed in three New York subway stations and Grand Central Terminal, a major New York rail hub, last year for a three-month, $1.1 million federally-funded study. The study found about half the rats took the bait and there was a 43 percent decline in the rat population in those areas.
New York Metropolitan Transportation Authority spokesman Adam Lisberg said SenesTech was supposed to conduct another study this year in more subway stations but did not end up doing a follow-up because SenesTech was focusing its efforts on a Massachusetts trial.
"We would welcome them to come back and do a phase two here," Lisberg said.
In Chicago, the CTA spends about $500,000 annually in pest control but Chase didn't know how much of that money is used for the poisonous rat traps. The agency focuses its rat control efforts on common rodent hiding places including subway sewers, older stations that have nooks and crannies, bus garages where bus drivers dump out the garbage riders have left behind on buses and CTA property near dumpsters, Chase said.
"Old facilities and the presence of garbage are a big challenge," Chase said.
Before the CTA began demolition work in the fall on the century-old Wilson Red Line stop in Uptown, some nearby residents expressed concern about rodents fleeing the station as their rat homes were destroyed. The CTA assured residents the agency would prioritize rat abatement.
An aide to Uptown Ald. James Cappleman said no complaints about rats have been reported to the 46th Ward office. Demolition work on the Wilson stop is expected to continue in the spring as part of a $203 million renovation project.
Holiday Bus and Train Tracker
Tuesday is the last day for the CTA's annual Holiday Train and Holiday Bus. The Holiday Train will be on the Yellow Line while the Holiday Bus will be on the No. 49-Western route.