Why do llama's hum?
Llamas hum for a few different reasons. Humming is a llama's
main form of vocal communication. Mother and baby (dam and cria)
will hum to each other, mom making sure cria is ok/ location of
cria, and cria will answer in kind. Llamas hum when they are
worried, anxious, and questioning. If you are with a llama long
enough (like weeks or months), you can start to tell which hum
means what. A happy llama does not hum, though.