Newborns are attracted to the smell of breastmilk, and experiments show that they will vigorously turn away from bitter or acidic smells such as vinegar, ammonia, or rotten eggs.
References
Shelov, S. P. (Editor-in-Chief). (2004). Caring for Your Baby and Young Child: Birth to Age 5. The American Association of Pediatrics. Revised edition. New York: Bantam Books.
Steiner, J. E. (1979). Human facial expressions in response to taste and smell stimulation. In H. W. Reese, H. W., & Lipsitt, L. P. (Eds.), Advances in child development and behavior. Orlando, FL: Academic Press.
