First off, there is nothing you can buy to put down, be it sulphur or lime or the so called snake repellent that will keep em away. Its all a false sense of security, and that will get somone hurt. Keep the grass low, and do not allow any junk to accumulate. You do not necessarily need to have water right there for cottonmouths to be around, but the water willl be fairly close. Copperheads like lumber and log piles or anyhting like that, and rattlers like to do a lot of sunbathing. I kill many rattlers, cotton mouths and copperhrads on my place every year. I have a huge swamp in the back 40, a stream and a pond. Lots of squirrels and field mice. Yes, I am paranoid with them as so far I have had 2 of my mini doxies bitten 2x each and another bitten once and then another bitten 2x and it did him in. I have some Diamondbacks but mainly Timber rattlers. They say activity will keep them away, but do not buy into it. With 10 mini doxies running around in a fenced in yard, I still shoot my fair share that is inside the yard or on the front porch sucking up the heat from the concrete. Once the weather is nice at my place you do not walk around early or late night without a flashlight. In the south snakes do not really go into deep hibernation like they do up in the more northern states, so on a nice warm day in January its not unusual to find them outside a burrow warming up. I live in south central Alabama, and the entire Gulf Coast area is prime snake heaven even in towns. I normally carry an old RG .38 spec with 6" barrel loaded with snake shot when outside, and it comes in handy fairly often. Last year I killed 13 rattlers, 3 cotton mouths and 7 copperheads. This year already I have 2 rattlers. Lots of luck and work on that youngin to make sure he stays away and gets ahold of an adult if he sees a snake.