Berserk llama syndrome (usually shortened to BLS), aberrant behavior syndrome, or berserk male syndrome (as it is more pronounced in males) is a psychological condition experienced by human-raised camelids, particularly llamas and alpacas, that can cause them to exhibit dangerously aggressive behavior toward humans. The term has been overused, however, and is sometimes inappropriately applied to llamas with aggressive personalities that are not truly "berserk".[1][2][3]