Cribbing is one of the various bad habits which horses can develop. It appears to develop as a result of boredom, in particular when a horse is confined to a stall for most of the day and has never been observed in horses which live in a natural environment (e.g. pasture based). With cribbing, the horse grabs an object (e.g. fence rail or feeding trough) with its front teeth, then arches its neck while pulling on the item, then sucks in air. Although the reason for this activity has not been proven, it is believed that the horse does it because it results in the release of brain chemicals (such as endorphins) which are pleasurable. The terms ‘crib biting’ and ‘wind sucking’ are also used.