There are many species of snakes in Ohio. Roughly about 24 or so. Out of all these snakes, only three are considered poisonous. That would be the Northern Copperhead, the Eastern Massasauga, and the Timber Rattler.
Copperheads have bitten more people in the U.S. than any other snake. Luckily the amount of venom injected in a single bite is not enough to be fatal in a healthy adult. However it is extremely painful. You can easily find them in rocky, wooded hillsides. When encountered, they usually retreat, but if aroused, they can vibrate their tales and strike wildly.
The Eastern Massasauga is also called the Swamp rattler and Black snapper. It has been recorded in more than 20 Ohio counties. However, sightings are rare and this snake is designated STATE ENDANGERED. They are usually very sluggish and don't offer to bite unless thoroughly aroused. Their venom is highly toxic. However, it has small fangs and does not inject enough to be fatal.
Finally, the Timber Rattler is the most dangerous snake in Ohio because of its large size. They can reach lengths of 6 feet. Luckily, most Timber Rattlers are mild in disposition and simply try to crawl away when encountered. If aroused enough they will defend themselves. These snakes are also designated as STATE ENDANGERED.
Nonpoisonous snakes are far more numerous in Ohio. But many are often mistaken for their more toxic relatives. Of all these snakes, the Black Rat Snake is the one most commonly slaughtered. My snake, Sirrius Black, is a Black Rat Snake. I am taking out into the public this summer to show any one who will listen that he is harmless and very beneficial. His main diet is rodents. With him around, there will not be mice or rats chewing on your electric wires or putting holes in your walls. I hope you come out to meet him and my other snakes and see that they are truly amazing and beautiful creatures.