Why are armadillos used for research?
Odd though it may seem, armadillos might someday help cure leprosy (Hansen’s disease). Researchers have found that the core body temperature of the armadillo is low enough to favor the growth of the leprosy-causing bacterium Mycobacterium leprae. While this microorganism has been grown in other types of animal tissue, no animal model had previously been found that regularly contracted the most virulent form of the disease (lepromatous leprosy). Because the bacillus only tends to grow in cooler parts of the body, such as the feet, nose and ears, large amounts of bacteria could not be grown (attempts to grow the microorganism in vitro have not been successful). The armadillo, however, has a lower body temperature than most mammals, resulting in rapid development of the disease following inoculation. Because of the armadillo, scientists have been able to develop a vaccine against leprosy. The nine-banded armadillo has become the principal source of M. leprae in biochemical and immunological research.
Although there has been some concern about humans contracting leprosy from wild armadillos, this is not a common occurrence. My understanding is that most instances of humans contracting leprosy from armadillos involve people who have eaten undercooked armadillo meat. (You can read more about this on the Armadillos as Food page.)
Because of their unique double-twinning, nine-banded armadillos are also studied to learn more about multiple births and other reproductive issues. Some researchers have also explored the possibility of using armadillos in HIV studies. In the past, the nine-banded armadillo has been used for skin and organ transplant experiments, tests of cancer-causing agents, and experiments on drug metabolism. The fact that one animal produces four identical young has been very helpful to scientists, because no experiment is acceptable without proper controls. Identical animals means that any differences seen between an experimental animal and the control animal are a result of the treatment, and not due to different genetic makeups.
McBee, K. and Baker, R.J. 1982. Dasypus novemcinctus. Mammalian Species 162: 1-9.
Storrs, Eleanor. The Astonishing Armadillo. National Geographic. June 1982. 161(6).