what kind of snake?

[cole]

Today I was outside cleaning up my yard, and in my little sister's sandbox i found a small maybe 10inch snake that was a dark brown with a diamond pattern on its back. When it saw me it went into that S position with the 1st 6 inches of its body off the ground and then the tail was pointed straight back flicking back and forth really fast. At first i thought it was a garder snake but i see them all the time and they never curl up like that, they always just try to run away and hide. But this one stood its ground and started snapping at my boots. Anyone know what kind of snake this could be?