Regurgitation is the process of bringing swallowed food back up into the mouth. This can happen in both humans and animals, often as a result of digestive issues or certain medical conditions. In some cases, it may occur naturally, such as when a baby infant brings up milk after feeding. In animals, particularly birds, regurgitation can serve a purpose, such as feeding their young. The parent bird will bring up partially digested food to provide nourishment. While regurgitation can be a normal behavior in some species, it may indicate health problems in others, requiring veterinary attention.