ectoparasites. Recorded also at Bossou. 3. See video. pelvic thrust See thrust. penile adduction See adduct penis. penile erection See erect penis. perforate Chimpanzees of Goualougo reopen termite exit/entry holes on the surface of epigeal nests after unsuccessfully attempting to open the holes by hand. Perforating twig tools are held with a precision grip as the tip is pressed into the surface of the mound. The end of the tool is used to push through the soil replaced by termites to seal the nest. Absent at Mahale. See video. pestle-pound See pound pestle. Petit Loango Study area of Pan troglodytes troglodytes in Petit Loango Faunal Reserve, Gabon. Research done by J. Yamagiwa and colleagues from 1994 to 1998. P pick ear Remove ear wax with finger. See sickness.