How do you use the moth balls to keep snakes away?
Put them around house close to Entries, be carefull if have Young children or pets; try buying "openproof" Rat-mouse bait stations & shoving the Mothballs in there first. Can get those at most hardware stores.
When you see the snake trow moth balls at it and it will run away :D
You find the snake holes and put on or two in there. Then you put one periodically around your yard.