It is an omnivore and eats grass, fruit, shoots, seeds, bird eggs, and small animals, and occasionally scavenges on carrion.

Males have canines, short antlers that usually branch just once near the base, and a large postorbital scent gland used to mark territories.

Males also have elongated 2–4 cm (0.79–1.57 in) long, slightly curved upper canines, which can be used in male-male conflicts and inflict serious injury.

Muntjacs are unique among the deer, having large, obvious facial (preorbital, in front of the eyes) scent glands used to mark territories or to attract females.

[11] The Southern red muntjac is also called "barking deer" due to the bark-like sound that it makes as an alarm when danger is present.

Adult males in particular are well spaced and marking grass and bushes with secretions from their preorbital glands appears to be involved in the acquisition and maintenance of territory.

Males often fight with each other over these territories, sufficient vegetation, and for primary preference over females when mating using their short antlers and an even more dangerous weapon, their canines.

During the time of the rut, territorial lines are temporarily disregarded and overlap, while males roam constantly in search of a receptive female.

Adults exhibit relatively large home range overlap both intersexually and intrasexually, meaning that strict territorialism did not occur but some form of site-specific dominance exists.

[13] Paleontological evidence proves that Southern red muntjacs have been around since the late Pleistocene epoch at least 12,000 years ago.

[14] The female Southern red muntjac deer is the mammal with the lowest recorded diploid number of chromosomes, where 2n = 6.

[14] Southern red muntjacs are hunted for sport and for their meat and skin around the outskirts of agricultural areas, as they are considered a nuisance for damaging crops and ripping bark from trees.