This species is found in large colonies, ranging from 20 to 100 individuals although much larger colonies (up to 5,000) have been reported. Desmodus rotundus roosts in moderately lighted caves with deep fissures, and in tree hollows. Common Vampire Bats can also be found in old wells, mine shafts and abandoned buildings. Roosts often smell strongly of ammonia because of the digested blood that has collected in the crevices and on the floors of the roosts (Mulheisen and Anderson 2001). Common Vampire Bats are limited to warm climates. It can be found in both arid and humid parts of the tropics and subtropics. It occurs up to 2,400 m asl (Ramirez pers. comm.).

It is hematophagous, meaning it feeds on blood. 

This bat is a social animal that hunts and lives in groups. Individuals live in colonies consisting of both males and females. In captivity, dominance hierarchies based on access to food were observed, but there is little conclusive evidence of complex hierarchies in the wild. Curiously, most close associations are formed between several females or females and their offspring; adult males do not form close social ties in the roost. Females frequent more roost site than males, making associations in many different places. The associations between females are maintained over many years. Wilkinson (1985, 1986) reported that although self-grooming occurs more often, social grooming is an important part of the Common Vampire Bat's behaviour. Social grooming usually occurs between females and their offspring, but it is also significant between adult females. The adult females participating in grooming are usually closely related or roost mates. Wilkinson (1986) found that social grooming has more to do with food sharing than with the removal of ectoparasites. In many instances, social grooming begins with one female approaching another and grooming her for as long as two minutes. The female being groomed then regurgitates part of her blood meal for the grooming female. It is also common to see females regurgitate food for their offspring.

This species occurs in Uruguay, northern Argentina, Paraguay, Bolivia and northern Chile, north to Sonora, Nuevo León and Tamaulipas (Mexico). It also occurs on Margarita Island (Venezuela) and Trinidad (Simmons 2005).

There is a need to promote education of people to prevent further colony elimination.