The blue duiker's enemies are pythons, mambas, large birds and monkeys often provide duikers with fruit and leaves, and it is not unusual to see duikers feeding below a troop of monkeys in the forest. They are specialised in their habitat requirements, and throughout their wide distributional range they are found only in forests, thickets or dense coastal bush. They commonly live in pairs, sometimes with sub-adult offspring.

Unlike many kinds of buck, blue duiker drink frequently, and are dependant on available water supplies. The duiker has a perfect camouflage due to its colouring, but as it moves about in the bush it flicks its tail, thereby exposing lighter hair underneath, which can be a giveaway to predators in the area. The newborn lamb has a much lighter coat, and is therefore also vulnerable to predation. The mother normally keeps her young hidden in the undergrowth. Usually a single lamb is born in September or October.