Expelling stick. Push stout stick into hole of tree or other cavity and stir it violently side to side or back and force with arm. Mahale chimpanzees try to expel rock hyraxes from cavities in rocks. Customary at Gombe, Mahale and Ta. 3. See video. extend Extend arm or leg to another individual. See video. extend arm as ladder Nishida: Caregiver extends arm upwards in tree, to allow infant to climb up easily, by making ladder with arms. See also aid in locomotion and extend leg as ladder. Absent in bonobos of Wamba. 7. See video. extend hand Goodall Extend hand. van Hooff Hold out hand: A variety of forms were observed. Most common is a form in which the actor, either sitting or standing, extends its arm