No established, permanent colonies of blood-feeding bats exist within the mainland United States. The term “vampire bat” refers to only three specialized species out of over 1,400 bat species globally, all found exclusively in the Americas. These nocturnal mammals are the only mammals that feed solely on blood, a diet known as hematophagy. The three species are the common, hairy-legged, and white-winged vampire bats.
The Actual Geographic Range
The most widespread species, the Common Vampire Bat (Desmodus rotundus), currently limits its permanent northern range to northern Mexico. This species requires warm, humid climates and is found in tropical and subtropical regions down to Argentina and Chile. The northernmost boundary of their habitat is approximately 31 miles (50 kilometers) south of the Texas border. While a single specimen of the Hairy-legged Vampire Bat (Diphylla ecaudata) was documented in extreme southwest Texas decades ago, these rare occurrences do not constitute an established population. Climate models suggest that rising temperatures may expand suitable habitat for the common vampire bat northward into parts of South Texas and Southern Arizona.
Common Bats Found in the United States
The prevalence of other, non-blood-feeding bat species in the United States often causes confusion. Of the roughly 45 bat species found in the US, more than 90% are insectivorous, meaning their diet consists entirely of insects. Species like the Mexican Free-tailed Bat and the Big Brown Bat are common throughout the country and act as natural pest control agents.
A single Little Brown Bat (Myotis lucifugus), for example, can consume hundreds of mosquito-sized insects in an hour. The collective insect-eating activity of US bat populations provides an estimated economic benefit of several billion dollars annually to the agricultural industry by reducing crop damage and the need for pesticides.
A small number of US bats, primarily in the arid Southwest, feed on sources other than insects. Nectar-feeding bats, such as the Mexican Long-nosed Bat, are important pollinators for desert plants like agave and saguaro cacti. The Jamaican Fruit Bat, found only in the Florida Keys, subsists on fruit. None of these bats feed on blood, distinguishing them from their southern relatives.
Addressing Public Health Concerns
Public concern about vampire bats often centers on disease transmission, specifically rabies. The risk of rabies is not exclusive to blood-feeding bats, as any mammal can transmit the virus. In the United States, bats are the animals most frequently identified as the source of human rabies cases, accounting for approximately 70 percent of deaths.
The actual risk of encountering a rabid bat remains extremely low, as estimates suggest that less than one percent of the overall US bat population carries the virus. On average, only one to three human rabies deaths occur each year in the country. Safety precautions should be taken with any bat, regardless of its species or diet, and contact should be avoided.
A bat that is active during the day, unable to fly, or found in a location like a bedroom may be sick and should not be handled. If any contact occurs, public health officials recommend seeking immediate medical attention for post-exposure prophylaxis.
The presence of rabies is a concern for livestock near the US-Mexico border. Monitoring and surveillance programs are in place to detect any northward range shifts of the common vampire bat.