Why Do Alpacas Hum? Alpaca Sounds and Communication

What does an alpaca hum sound like?

An alpaca hums with its mouth closed, producing a gentle, nasal “mmm” that can rise or fall in pitch. It is quiet enough that you often need to stand fairly close to hear it, but within a herd it carries well. Some hums are short and questioning, others are long and repeated, and different situations tend to produce slightly different tones.

Humming is the sound most people notice on alpaca farms, because the animals do it so often. It is not a song or a purr, and it is not a sign of illness on its own; it is a normal part of everyday alpaca conversation.

Why do alpacas hum? The main reasons

Researchers and breeders describe several situations in which alpacas hum:

• Mother and cria contact. When a cria (baby alpaca) is born, mother and baby hum back and forth almost constantly. This helps them recognize each other’s voice and keeps the young animal close in the herd.
• Keeping in touch. Herd members hum to each other while grazing or moving, a low-key way of saying “I’m here”.
• Separation. An alpaca cut off from its group, for example in a separate pen or trailer, often hums repeatedly and more urgently. Because alpacas are strongly social, being alone is stressful for them.
• Curiosity. New objects, new people or a change in routine can set off questioning hums.
• Discomfort or worry. Hot weather, handling, shearing or feeling unwell can all produce more frequent, strained hums.

Because the same sound covers such different moods, experienced keepers read humming together with the alpaca’s posture, ears and behavior rather than on its own.

Other alpaca sounds

Humming is only one part of a surprisingly varied alpaca vocabulary:

• Alarm call. On seeing a dog, fox or other threat, an alpaca gives a loud, shrill, repeated braying call. The herd then lines up with heads high, staring at the danger, and may move together or chase small predators.
• Snort. A short, sharp snort warns another alpaca that it is too close or should back off.
• Grumble. A low, gurgling grumble is a warning, often heard during disputes over food or space, and can be followed by spitting.
• Cluck. A soft clicking or clucking sound, a little like a hen, is used by mothers worried about their crias and by males in friendly approaches.
• Scream. Alpacas can scream very loudly when frightened, handled roughly or attacked.
• Screech. Fighting males make a high-pitched, bird-like screech while chasing and wrestling rivals.
• Orgle. During mating, which takes place with both animals lying down and often lasts 20 minutes or more, the male makes a continuous gargling sound known as orgling.

Llamas use much the same set of sounds, including humming and alarm calls, so the two species can understand each other well when kept together. See our llama profile for more on alpacas’ larger relatives.

Body language: ears, neck and tail

Most alpaca communication is silent. A herd keeps its peace through posture, and sounds are often only the final step.

• Ears. Ears pricked forward show alertness and interest. Ears pinned flat back, especially with the nose raised, signal annoyance and a possible spit.
• Head and neck. A high head and long, upright neck show alertness or dominance. A submissive alpaca lowers its head and neck and may crouch.
• Standing side-on. A male defending his position may turn sideways to a rival with his ears back, a display called “broadside”.
• Tail. The way an alpaca carries its tail also changes with its mood and rank, and keepers read it together with the ears and head.
• Staring. A group of alpacas staring in one direction, frozen and silent, usually means they have spotted something worrying.

Spitting as communication

Spitting is the alpaca’s best-known signal, and it is mostly aimed at other alpacas. A female that is already pregnant spits at a male to refuse mating, and alpacas spit to keep herd mates away from food or personal space. The warning signs usually come first: ears back, chin up, grumbling and puffs of air. People are usually hit only when they stand between two arguing animals. Llamas behave in the same way, as explained in Why do llamas spit?.

Humming in alpacas vs other animals

Humming is unusual among farm animals. Sheep and goats bleat, cattle low and horses neigh, but camelids such as alpacas and llamas rely heavily on soft, close-range hums. This makes sense for animals that live in tight family herds on open Andean grassland, where staying in contact quietly may help avoid drawing the attention of predators such as pumas.

The short answer, then, is that an alpaca’s hum is a flexible contact call: the same simple sound helps mothers find their babies, keeps the herd together and tells others how an animal is feeling. To learn how alpacas differ from their bigger cousins in looks and temperament, see alpaca vs llama.