I don't recommend doing any hiking in weedy or wooded areas wearing just a pair of sneakers. I will only wear over-the-ankle leather boots.
That said, I must admit that I have just turned 68 years old and have never seen a poisonous snake in the wild while hiking.
The only poisonous snakes I have seen were copperheads on the practice grenade range at Camp Geiger in North Carolina while in Marine Corps infantry training. It was a cold morning and these snakes were inactive, curled up in a ball next to a log barricade. Needless to say, we didn't use that barricade any more for the training exercise we were doing that day.
Here are some other facts about poisonous and nonpoisonous snakes from the Web site of the Merck Co.:
* Bites from nonpoisonous snakes rarely produce any serious problems.
* About 25 species of venomous (poisonous) snakes are native to the United States. The venomous snakes include pit vipers and coral snakes.
* Of the roughly 45,000 snakebites that occur in the United States each year, fewer than 8,000 are from venomous snakes, and about six people die. Fatal snakebites are much more common outside the U.S.
* In about 25 percent of all pit viper bites, venom is not injected. Most deaths occur in children, older people and people who are untreated or treated too late or inappropriately.
* Rattlesnakes account for about 70 percent of poisonous snakebites in the United States and for almost all of the deaths. Copperheads and, to a lesser extent, cottonmouths account for most other poisonous snakebites. Coral snake bites and bites from imported snakes are much less common.
* The venom of rattlesnakes and other pit vipers damages tissue around the bite. Venom may produce changes in blood cells, prevent blood from clotting and damage blood vessels, causing them to leak. These changes can lead to internal bleeding and to heart, respiratory and kidney failure. The venom of coral snakes affects nervous system activity but causes little damage to tissue around the bite. Most bites occur on the hand or foot.
In my opinion, the best defense against snake bite is to watch where you put your feet. Don't just blindly plant your foot into an area where you can't see what you are putting your foot down on.
I'm told that you can always tell when a copperhead is around because they smell like cucumbers. Though if it were me, I'd have to get close enough to the snake to get bitten on the nose because the old schnozzola isn't what it used to be.
Use caution and you should have no problem, so get on out there and enjoy Mother Nature.