K.P.
(My son doesn't have a problem, but this is the advice that was given to a friend of mine who's 13 month old is biting. Hope it helps!)
When my daughter turned about 14 months, she suddenly took to all sorts of acting out behaviors - mostly directed at me, but occasionally at my husband. She was still nursing at the time, and would hit me while nursing, for example. She's always grin first, then do it. Also, she'd try to hit when we were playing, or if I was holding her, and then all sorts of kicking started, especially during diaper changes.
I was at my wit's end as to how to handle it. I didn't think she was old enough for a true "time out" where I'd put her in her room or remove her from the action because by the time I'd get her in the right spot, I knew she'd have no comprehension of what the "time out" was related to. All the books I read talked about time outs and explaining, but they also were all addressing this behaviour in their "18 month" (or older) sections.
I asked my daughter's pediatrician about it and got GREAT ADVICE. She said that whenever my daughter did something like biting, hitting or kicking, I was to hold onto the offending appendage (or perhaps put my hand on her mouth) so she could identify WHAT we were talking about, specifically, and then say "NO Hitting!" (or kicking, or biting) very firmly. Then I was to immediately put her down on the floor / ground and turn my back to her.
I was to stay like that, with my back to her, until she crawled or walked around to face my front and was seeking to "make up" (ie, not crying or having a tantrum anymore but sincerely looking for my attention). Then, I'd just pick her up and move on as though nothing happened.
This was great for me because it was an immediate reaction that had a "punishment" that was very passive. Yes, my daughter really got upset when I turned my back to her, but she very quickly figured out that if she came to me with a different attitude, I'd respond. She also stopped the behaviour almost immediately. I only employed this method a few times, maybe 5 at the most, and it all changed.
Maybe she'd just turned a corner in her development, or maybe the method was really effective. Either way, I felt like I was empowered to respond to her in a way that I felt was fair and working on her level of comprehension at that developmental age.
Good luck!