The nostrils are widely open and face forward, and two flaps of skin on the upper rim of the nostrils form two little peaks that almost touch the forehead. In Pygathrix these flaps lie flat. Very little is known about snub-nosed langurs. They inhabit high mountain forests, up to about 4,000 meters, but may descend to lower elevations in winter. Part of their range is covered by snow for more than half the year.
Most activity takes place in trees, but some feeding and social interaction occurs on the ground.
If frightened, the animals flee through the upper levels of the canopy at great speed. Normal daily foraging movement is about 1,000-1,500 meters. The diet seems to consist largely of young fir and pine needles but also includes bamboo shoots, buds, fruits, and leaves. Troops of over 100 and even up to 600 individuals have been reported, though such groups may be divided into many units, each containing one dominant male, 3-5 females, and young. The male secures his position by fighting other males.