They have scent glands on the underside of their arms, and near their tails. This suggests that the smell is an important sense. Lemurs are quadrapedal, however, the actual gait they use may vary. The tail is used in balancing when they are walking on horizontal branches. They sleep in a semi-erect posture, with the head resting between the knees, and the tail and hands wrapped around the branch.
Lemurs live in large groups consisting of females and males.
There are usually more males than females in the group. Females tend to be dominant. Sexual behavior is seasonal, probably ocurring between April and June. Lemurs come in all sizes. Closely related Indris are the largest and there are lemurs that are about the size of a mouse.