Roe - dawn ruminating

In his 2007 book Deer Watch, Richard Prior notes that cud chewing seems to be a relaxing activity for deer; they lie with eyes half-closed and a slight hiccup and ripple in the throat signals the re-arrival of a ball of food.
Food passes down the oesophagus into the rumen, where it sits and becomes mixed with microbes. An expansion of the chest produces a vacuum in the upper rumen and allows some of the plant material to be sucked back up into the oesophagus, where peristaltic movements force a clump of cud (called a bolus) up into the mouth. When in the mouth, the bolus is pressed against the roof by the tongue and excess water is swallowed before chewing recommences.
Taken from - www.wildlifeonline.me.uk/anim...