Surface locomotion is quadrupedal, the soles of the feet and the middle phalanges of the fingers being placed on the ground. Though capable of bipedal movement, such movement never exceeds 60 feet. Gorillas are reluctant to cross even the shallowest of streams. Platform nests are built for sleeping. Although they are nearly entirely vegetarian, some will accept meat or take insects.
Gorillas are social, living in groups.
When two groups meet they may ignore each other, temporarily associate, or express hostility. Groups can range from 2 to 30 in number and, if a group has more than one mature male, one will be dominant. The estrous cycle lasts 26 days, with estrus being 1 to 3 days. Physiologic sexual maturity is 8 years for females and 10 for males, although breeding doesn't usually occur until 10 in females and 15 in males. During a lifetime a female usually only gives birth to 2 or 3 surviving infants.