Regurgitation is the expulsion of material from the pharynx, or esophagus, usually characterized by the presence of undigested food or blood.[1]
Regurgitation is used by a number of species to feed their young.[2] This is typically in circumstances where the young are at a fixed location and a parent must forage or hunt for food, especially under circumstances where the carriage of small prey would be subject to robbing by other predators or the whole prey is larger than can be carried to a den or nest. Some bird species also occasionally regurgitate pellets of indigestible matter such as bones and feathers.[3]
It is in most animals a normal and voluntary process unlike the complex vomiting reflex in response to toxins.