For your peace of mind and their advanced comfort. Colic in infants may be caused by a combination of in?uences including ingesting air during feeding. The new advanced comfort range from Closer to Nature is specially designed to help reduce air bubbles in the milk and to encourage a good latch-on to help reduce the risk of baby ingesting air during feeding. The air vents down through the tube and into the air-space at the base of the bottle, completely bypassing the milk.