K.F.
I'm breastfeeding my fourth child and the thing that has always worked for me is a LOUD and quick NO when he/she bites. It startles the baby, sometimes they cry a bit, but it's always stopped my kiddos. The 3rd child I breastfed until 20 months and only got bit once or twice. I'm now breastfeeding my 4th and she started biting a couple weeks ago and I yelled no at her loudly. She pulled away and smiled (the stinker) but stopped during that session. A couple days later she bit me and before I could yell no she pulled away and started shaking her head no and smiling. Can't be mad when she is so darn cute, lol. Luckily she is 7 months with no teeth yet :) Good luck