Red-shanked doucs cannot grasp things with their tails. They use their tails for balance instead. They use arms and legs to move through the forest. They follow the same routes. The adult males lead the group, the females and very young doucs are in the middle, and young males go last. When the doucs sense a predator or other danger, they flee very quietly through the trees. They spend most of their time eating, digesting their bulky food, sleeping and grooming each other's fur. They communicate with facial expressions and sounds. The low-pitch grow indicates threat, and short and hash distress squeal.