As Halloween brings vampires out of folklore and into the spotlight, Colombia’s real blood-feeding bats have a story that spans cattle ranches and medical laboratories. A 2026 study identified 88 municipalities where cattle face a high modeled risk of rabies transmission from vampire bats. The animals have also inspired research into substances that could help dissolve blood clots.
Colombia is home to three vampire bat species: the common vampire bat (Desmodus rotundus), the white-winged vampire bat (Diaemus youngi) and the hairy-legged vampire bat (Diphylla ecaudata). All three are native to Latin America, but they have different feeding habits. The common vampire bat is the species most closely associated with livestock and rabies transmission.
How big are vampire bats?
Despite their fearsome name, vampire bats are surprisingly small, roughly the size of a small mouse. The common vampire bat, the species most associated with cattle, weighs around 30–40 grams (1–1.4 ounces). Its body is about 7–9 centimeters (3–3.5 inches) long, and its wings span roughly 35–40 centimeters (14–16 inches) when extended.
The other two species are similar in size. The white-winged vampire bat and the hairy-legged vampire bat also feed on blood, but their diets differ from that of the common vampire bat. The white-winged and hairy-legged species feed mainly on birds, while the common vampire bat feeds primarily on mammals, including cattle.
Where do Colombia’s vampire bats live?
The common vampire bat ranges from Mexico through much of Central and South America, reaching as far south as northern Argentina. In Colombia, it occurs in a variety of tropical environments, from humid areas to relatively dry regions. It shelters in caves, tree hollows and abandoned buildings.
The three species do not all rely on the same food sources. Common vampire bats feed mainly on mammals, including cattle, horses and wild animals. White-winged and hairy-legged vampire bats feed primarily on birds. This difference helps explain why the common vampire bat is the main concern when agricultural authorities assess rabies transmission from bats to livestock.
Vampire bats can also move on the ground in a way that surprises people who associate bats only with flight. The common vampire bat can walk, run and hop using its strong hind limbs and modified thumbs, an unusual ability among bats.
Why vampire bats threaten cattle
Vampire bats do not suck blood like the creatures of legend. They use their sharp teeth to make a small cut in an animal’s skin and lap up the blood. Their saliva contains anticoagulant substances that slow clotting, allowing blood to continue flowing while they feed.
That adaptation also makes the bats a concern for livestock owners because they can transmit rabies to cattle. Infected animals can die, and outbreaks can create substantial costs for farmers and agricultural authorities.
A study published in Revista MVZ Cordoba on March 23, 2026, mapped areas where cattle face a higher risk of rabies transmission from vampire bats. Researchers used historical outbreak records and environmental data to identify areas where authorities should prioritize prevention.
The model classified 88 municipalities as high risk, with the greatest concentration in the Caribbean region and additional areas along the Andes.
The study also found that 87.1% of Colombia’s land area met the model’s threshold for some level of potential transmission risk. This does not mean rabies has been detected across that area. Rather, it means environmental conditions there resemble those found in places where transmission to livestock has occurred previously.
The model identified distance from forests and cattle density as important factors, alongside temperature and rainfall. The resulting risk map has helped inform vaccination planning, although researchers say more years of vaccination data are needed to assess the program’s effectiveness.
Do vampire bats attack humans?
Vampire bats can bite people, but humans are not their usual food source. The common vampire bat feeds mainly on mammals, and livestock provides a source of blood in many rural settings. The other two species feed primarily on birds.
The health concern is rabies. A bite from an infected bat can expose a person to the virus, and rabies is almost invariably fatal once clinical symptoms develop. Anyone who may have been bitten should wash the wound thoroughly with soap and water and seek urgent medical assessment. Bats should never be handled with bare hands, even if they appear injured or inactive.
The risk to people is one reason public health and wildlife authorities advise against touching bats or attempting to remove them without professional help.
How vampire bat saliva inspired medical research
The same saliva that helps vampire bats feed has attracted the attention of medical researchers. One anticoagulant protein is called draculin, a name drawn from the vampire legend. Other compounds in vampire bat saliva have inspired investigations into ways of breaking down blood clots.
One example is desmoteplase, an enzyme derived from vampire bat saliva that helps activate the body’s clot-dissolving system. Researchers have studied it as a possible treatment for ischemic stroke, which occurs when a clot blocks blood flow to part of the brain.
The aim is to restore circulation before a lack of oxygen causes further brain damage. Clinical trials produced mixed results, however, and desmoteplase did not become a routine stroke treatment. The research illustrates how a biological adaptation that helps an animal survive can offer scientists ideas for potential medical applications.
For Colombian livestock authorities, the immediate priority is to use the risk map to guide rabies prevention and vaccination, particularly in municipalities where the model predicts the greatest danger. Updated outbreak records and vaccination data will help determine whether those efforts are reducing the risk.
For researchers, vampire bats remain a source of biological compounds worth investigating. Their feeding habits have consequences for livestock health, and their saliva continues to raise questions in medical science.