Lever open: Use stick to enlarge entrance. Customary at Gombe, Ta, Lop, and Goualougo. Absent at Mahale. lick Plooij LIK. Repeatedly stroke with tongue. See video. lick lips Lick away items on lips. See video. lick rock Lick rocks at few sites along shore of Lake Tanganyika or in riverbed of large rivers. More often in dry than wet season. May continue an hour. At Mahale, seen in chimpanzees of B, K, M and L groups. Nutritional significance unknown. Rocks licked not salty to human taste. Not seen at Gombe. Category. See video. lick snot See eat nasal mucus. lick wood Licks de-barked surface of dead trees such as Pycnanthus angolensis, Ficus capensis, Ficus vallis-choudae, Garcinia huillensis, etc., with extended upward laps of tongue. Surface exudes some sugar