Alligators often engage in violent fights over territories and mates, and scientists have puzzled over why their wounds rarely get infected.

Now researchers think the secret lies in the reptiles' blood.

Chemists in Louisiana found that blood from the American alligator can successfully destroy 23 strains of bacteria, including strains known to be resistant to antibiotics.

In addition, the blood was able to deplete and destroy a significant amount of HIV, the virus that causes AIDS.

Study co-author Lancia Darville at Louisiana State University in Baton Rouge believes that peptides—fragments of proteins—within alligator blood help the animals stave off fatal infections.

Such peptides are also found in the skin of frogs and toads, as well as in Komodo dragonsand crocodiles. The scientists