I think even if you "move them away," they will come back. They are probably there because they have a food source there. If you get rid of the food source (insects and mice), you'll get rid of the snakes as well. I'd suggest trimming your lawn shorter, trimming out your bushes, and maybe laying out some rodent repellents or something like decon. Another thing you might try is to find a way under your porch and lay out something like bark or something like that. They obviously like the "bedding" you've provided for them.
And by the sounds of it, it's hard to get under there so it provides a good nesting hole for them as well.
Bottom line... get rid of the food and the habitat, and you'll get rid of the snakes.