Slow lorises are one of three species of loris maintained at the Lemur Center (the others are pygmy slow lorises and slender lorises). All three of these species are members of the family Lorisidae which includes lorises, galagos and pottos and consists of 9 genera and 8 species found in Africa south of the Sahara, southern India, Sri Lanka, southeastern Asia and the East Indies. Lorises have a tail either very short or completely absent, and their heads and eyes are round, with small ears which are almost completely hidden by fur. The forelimbs and hindlimbs of lorises are nearly equal in length.

All lorises have extremely strong fingers and toes, and they are capable of maintaining a powerful grip with either hands or feet for astonishingly long periods of time. They are arboreal and nocturnal, sleeping by day in hollowed out trees, tree crevices or branches. Generally they sleep curled up in a ball, with their heads tucked up under their arms. When they move, they do so with slow deliberate hand-over-hand movements, moving along as easily under a branch as above. They are capable of moving quickly if alarmed, but they do not jump or leap.

Worldwide, there are over 107 slow lorises in captivity at recognized captive breeding facilties. In North America, there are 40 slows in captivity. Slow lorises are not officially recognized as endangered in the wild. Currently, the DLC does not maintain any breeding pairs of slow lorises, although long range plans call for the continued maintenance of this species at the Center.