Avent Natural Response Bottle The Natural Response Nipple is designed to mimic the natural feeding process, offering a more intuitive experience for your baby. Unlike traditional nipples that provide a continuous flow, the Natural Response Nipple releases milk only when your baby actively sucks, encouraging them to control the feeding pace. his may require some adjustment for both you and your baby, as it differs from the constant flow of many other nipples. However, once your baby acclimates to this natural rhythm, they can seamlessly transition between breastfeeding and bottle feeding.