Why don't we lose weight evenly? [View all]

I've been dieting (Atkins) for a couple of months and I've lost about 12 lbs. - but it's off my face and limbs, not my big fat rear end. My legs are thinner but they never were fat. My hands are starting to look bony (but it's nice to be able to get rings off and on easily). How come my butt won't go away? I'm afraid I'll eventually look like a wood tick.