My DD has done this to me off and on since week 2. I have a friend who was a lactation consultant when she lived in WA. The advise she gave me was to take her off straight away, firmly tell her NO and to use an iliteration. The iliteration goes 'nibbling nipples naughty'.

It has worked for me, and K only tries to bite occasionaly now and normally only if her gums are hurting her.

HTH.