They usually mate for life. According to Beastly Behaviors the females are the initiators when their cycle of menstruation is in process. They let the male know they are ready and the couple mate. Once a female gorilla becomes pregnant and has a kid she will be celibate for two to four years. Because gorillas dedicate this time to their young, their young are able to experience the group culture and learn through their experiences.
Gorillas use their fingers, eyes, and lips to examine and clean.
They clean their skin, hair and nails. This behavior can basically be compared to humans visiting a beauty salon. Gorillas play games that I played when I was a kid. Through observation at the zoo it is noticed how gorillas do somersaults, spin, climb, jump, run, slide, and wade in the water. Because the gorillas received proper care growing up they are able to be successful members in their group through social interaction.