I've caught Rex eating his own poop twice today. Is this a normal puppy thing? The first time it was outside during potty time, so he didn't get much. Second time was when he was bad inside (I was bad too, I let him out of my sight for a sec to get my son something). I walked over to him and saw him chopping on something and then the smell hit me! *gags* I imagine it's a normal thing, since mommy used to do it for him, but what do I do to stop it, or will he just grow out of it?