When threatened, the muntjac emits barking-like cries, hence its other name: "barking deer". When a predator approaches, it warns its fellow deer and other potential "prey" species. Highly territorial, the male is aggressive towards other males. Solitary and active mainly at dawn and dusk, the muntjac remains hidden in the grass during the day. The breeding season can take place throughout the year. The newborn, with its spotted coat, remains hidden in the thickets. At around 6 months, it will become independent and leave to establish its own territory.

The male has retained a primitive character: two short antlers carried on a very long pivot and large canines useful in combat for access to females. Equipped with large tear ducts, it marks all the supports it finds in its territory.

The Indian muntjac is the mammal with the fewest chromosomes: 6 for females and 7 for males! The Reeves' muntjac, on the other hand, has 46!

Reeves' muntjacs, a species native to China, were introduced to England to populate Woburn Abbey Park, but escaped at the end of the 19th century. Joined by individuals that escaped from other parks or were deliberately introduced, this small Asian deer settled in the centre and south of the island, then colonised Wales... With no predators, except for foxes that may attack fawns, hunting is permitted to regulate the population.