Eulemur and Petterus lack the antebrachial and brachial glands of Lemur and Hapalemur but possess perianal glands not seen in Varecia, Lemur, or Hapalemur. They are further distinguished from Lemur by a suite of dental characters that include smaller third upper and lower molars, distinct protostyle development on the first and second molars, a more developed anterior basin in the posterior lower premolars, and more continuous crests in the trigonids and talonids of the molars. All species are arboreal forest dwellers. They are active, quadrupedal animals that run and walk on horizontal and diagonal branches and are capable of leaping to and from vertical and horizontal supports. Resting postures range from sitting upright to lying sprawled on a horizontal branch.
Most activity is diurnal.
Social organization in Eulemur is variable. Lemurs appear to be territorial. There usually is a single young, though twins are not rare. Lemurs thrive in captivity and are often exhibited in zoos. The relatively high population densities reported in field studies may be misleading in that they generally apply only to small, protected reserves.