Regurgitation (digestion)

Regurgitation is the expulsion of material from the pharynx, or esophagus, usually characterized by the presence of undigested food or blood.

[3] It is in most animals a normal and voluntary process unlike the complex vomiting reflex in response to toxins.

Regurgitation of a person's meals following ingestion is known as rumination syndrome, an uncommon and often misdiagnosed motility disorder that affects eating.

In times when food is scarce, siblicide may occur, where the dominant chick kills its younger sibling in order to sequester all of the resources of the parents.

During their idle time, they chew the regurgitated food (cud) and swallow it again, which increases digestibility by reducing particle size.

Flesh fly , from the family Sarcophagidae "blowing a bubble". One explanation for this behaviour is that it concentrates the fly's meal by the process of evaporation. The diet of the flesh fly is very high in water content. The fly regurgitates the liquid portion of the food, holds it while evaporation reduces the water content and the fly then swallows a much more concentrated meal without the water content. This continues until sufficient amount of liquid is left for the fly. – Australian Museum
Moorhen chick being fed regurgitated food by an adult
Eastern Bluebird regurgitating food