Hi Kim

I have never heard of a rat snake seeking out pond

there are however water snakes that are black - and some are deadly

dont confuse the rat snake with other species
so easily done

best way forward i would say is -- identify the species at hand

some info on the black rat of ohio can be found at http://www.oplin.org/snake/fact pages/rat_snake_black/rat_snake_black.html

"Local Habitat
Forests, rocky hillsides with large trees, farmlands and old fields"

you can check out other reptiles of Ohia at
http://www.dnr.state.oh.us/wildlife/Resources/reptiles/reptiles.htm

regards
Lynx