The highest ranking animal dominates all, the second highest all but the first, the third highest all but the first two, etc., down to the animal subordinate to all. Definition from Hurnik et al., 1995. Lip-curling is most noticeable in male ungulates when in proximity to estrous also be exhibited by female bovines when close to estrous peers. Definition from Hurnik et al., 1995. A rhythmical smacking action of the lower lip toward the upper lip.
Lip smacking is exhibited by some horses when under saddle or in unfamiliar environments.
Lip smacking is thought to be indicative of mild excitement and is considered to be a nuisance vice. Definition from Hurnik et al., 1995. To attend to sound stimuli. Definition from Hurnik et al., 1995. Definition from Hurnik et al., 1995.