DS is only 8.5 months, but has 6 teeth. He likes to suck/chew/bite things, which I'm fine with as long as they are teething toys or blankets or bibs, etc. What I'm NOT fine with is when he does it on my arm/shoulder/etc. Does he really know not to do it if I say "no" now? Most of the time he does it is when I'm trying to rock him to sleep and he gets my shoulder - last night I just kept saying NO and put him down on the ground, which made him cry harder (he's usually crying/whining when I'm rocking him b/c he's tired).