The Lake Erie water snake, a subspecies of the northern water snake ("Nerodia sipedon"), lives in the vicinity of Ohio's Put-in-Bay Harbor and had been placed on the threatened species list. By 2010, the water snake population was over 12,000 snakes. While they have a non-venomous bite, they are a key predator in the lake's aquatic ecosystem since they feed on mudpuppies, walleye, and smallmouth bass. The snake is helpful in keeping the population of goby fish in check. They mate from late May through early June and can be found in large mating balls with one female bunched with several males.