why do bats lick people

The Deep Dive

The phenomenon of bats licking people is almost exclusively attributed to the three species of vampire bats: the common vampire bat (Desmodus rotundus), the hairy-legged vampire bat (Diphylla ecaudata), and the white-winged vampire bat (Diaemus youngi). These bats are found only in Central and South America. Unlike popular myth, they do not "suck" blood. Instead, they land stealthily on a sleeping animal or person, use specialized heat sensors in their noses to locate warm blood vessels close to the skin's surface, and then employ razor-sharp incisor teeth to make a superficial, painless incision, often without waking the host. Their saliva contains powerful anticoagulants, such as Draculin, which prevent the blood from clotting and keep it flowing freely. They then lap up the exuding blood with grooves on their tongue, consuming only about a tablespoon per feeding. This highly specialized feeding strategy, known as hematophagy, has evolved over millions of years, making them unique among mammals. The bat's small size and quiet approach allow it to feed for up to 30 minutes undetected.

Why It Matters

Understanding why certain bats lick people is crucial for public health and wildlife conservation. While most bats are harmless and ecologically vital, vampire bats can transmit diseases like rabies, posing a risk to livestock and, less commonly, humans in affected regions. This knowledge helps communities implement vaccination programs for animals and educate people on safe interactions with wildlife. Furthermore, the unique biochemical properties of vampire bat saliva, particularly its anticoagulant compounds, are being studied by scientists for potential medical applications. These compounds could inspire new treatments for human conditions like strokes, where preventing blood clots is critical, demonstrating that even a seemingly unsettling behavior can yield valuable scientific insights.

Common Misconceptions

A widespread misconception is that all bats are bloodsuckers or that vampire bats are aggressive, actively seeking out humans to attack. In reality, only three of over 1,400 bat species feed on blood, and they primarily target livestock like cattle, horses, and poultry, not usually humans unless people are sleeping unprotected outdoors in their habitat. Another myth is that vampire bats "suck" blood like a mosquito or with fangs. They actually create a small incision and then lap up the flowing blood, aided by unique anticoagulants in their saliva, which prevent the blood from clotting, making the process more like a gentle lick than a forceful suck.

Fun Facts

• Vampire bats are surprisingly social creatures, known to share regurgitated blood with roost mates who failed to find food, preventing starvation within their colony.
• The anticoagulant found in vampire bat saliva, named Draculin, is being researched for its potential use in human medicine to treat stroke victims by dissolving blood clots.