incursion. Patrol crosses group boundary and invades territory of neighboring group to attack its members or to explore for resources such as food or mates. Recorded at Gombe, Mahale, Kanyawara, Ngogo, and Ta. 3. investigation probe See probe. investigatory probe See probe. invitation slap See slap in invitation. invitation stamp See stamp in invitation. invite See solicit. I J J join play Small infant rushes into vigorous play between seniors and interferes with them by approach, touch, slap, hit, kick, wedge, hug, mouth, etc. Infant rarely allowed to join. Adult, mother, adolescent or juvenile also joins play group of immatures and often succeeds in playing with one or two of them. See video. jump See leap and hop. juvenile Weaned youngster follows mother in daily ranging most of