Due to relatively small bodies, alpacas tend to seek shelter when in danger. On the other hand, llamas display agressiveness while in danger. They may kick, scream, spit and charge potential predator.
Their length ranges from 0.9 to 6.1 meters, and their weight ranges from 3 up to 580 kilograms.
The biggest of the genus is the great hammerhead. The record holder is a female caught in 2006 who weighed almost 581 kilograms. The reason for her unusual weight, however, was pregnancy.