New York City's rat problem isn't exactly new, and there have been numerous extermination proposals over the years that have attempted to get it under control, so the city's trying a new tactic. According to a report from Bloomberg Businessweek, NYC'S Metropolitan Transportation Authority (MTA) is planning to sterilize female rats with the hopes that the rat population will be cut by up to 75 percent. The MTA is starting up a pilot program where its partner SenesTech will study rat behavior in the subways with the goal of having them ingest the company's ContraPest product, which would make a female rat sterile within a matter of days.

SenesTech will specifically be examining the rats' feeding habits and preferred foods, which will help the company tailor its ContraPest dosages to NYC's rats specifically. The ContraPest will be distributed two ways — as an edible and also as a liquid, and the plans call for distributing it in the subway's trash rooms, an area with obvious attractions for the city's rat population. Ideally, the MTA's rat population will eventually be knocked down significantly, but will not be eradicated entirely — that would just encourage a new rat population to move in on the abandoned territory. "Rats are territorial, so you want to maintain a very low population that keeps other rats from migrating in," says SenesTech co-founder Loretta Mayer.