Infants begin to break contact with their mothers after five months, but only for a brief period each time. By 12 months old, infants move up to from their mothers. At around 18–21 months, the distance between mother and offspring increases and they regularly spend time away from each other. In addition, nursing decreases to once every two hours. Infants spend only half of their time with their mothers by 30 months. They enter their juvenile period at their third year, and this lasts until their sixth year. At this time, gorillas are weaned and they sleep in a separate nest from their mothers. After their offspring are weaned, females begin to ovulate and soon become pregnant again. The presence of play partners, including the silverback, minimizes conflicts in weaning between mother and offspring.