The vicuña, a graceful yet fast animal, has a thick brown coat that protects its body against the cold in its habitat. The vicuña, because of its warm coat, is able to tolerate the cold, ice and snow. The male feels most at home and happy when it’s among a group of about 5-15 females. This male vicuña will alert the females if any danger comes so that the female vicuñas can quickly run away. Younger males without a female harem will form their own groups. When the male fights, it will usually spit at the other vicuña. The vicuña can run very fast, at about 29 miles per hour (47 kph). These animals usually eat grass, and also eat small plants.

The vicuña is known for its good eyesight. Its hearing is somewhat good but its sense of smell is not good at all. Almost right after a vicuña is born, it can stand and walk very well. It suckles for about ten months.

It is generally thought now, given the DNA evidence, that the alpacas descended from the vicuña line thousands of years ago.