Llamas, alpacas, guanacos, and vicuñas are in the Camelidae family but are not true camels. Early Spanish explorers/invaders called them “Peruvian Sheep!” They are all native to the high, dry, mountainous regions of South America. Not surprising given their (cold) native environment, their fiber has a high degree of insulation. They – like camels – have long provided humans with many resources: fiber, food, leather, transportation (riding or packing), and fuel (from burning their dried dung). They chew their cud and will spit too.
Llamas (Lama glama): Llamas are large. A full-grown llama measures between 5.5 and 6 feet (1.7 to 1.8 m) at the top of its head and weighs between 280 to 450 pounds (130 to 200 k). They also make excellent flock guardians. These camelids have been known to kill wild dogs and coyotes.
Llamas are two-coated: their undercoat is fine and down-like (and keeps them warm), and their guard hair (no crimp) sheds moisture and debris. Given the cellular structure (hollow core) of their coats and lack of lanolin, their fiber is hair, not fur.
The fiber from llamas raised in their native environment ranges from 20 to 40 microns compared to 20 to 22 microns for U.S. llamas. Llama hair tends to be less itchy, softer and warmer than wool. (Pic source)
Alpacas (Lama pacos): Not as large as their cousin the llama, adult alpacas stand between 2.5 and 3.5 feet at their shoulders and weigh between 106 and 185 pounds (48 and 84 k). Like llamas, alpacas have hair (not fur), that is hollow, a double coat and lack lanolin. Alpaca yarn is also less itchy, softer and warmer than wool. The average micron count of alpaca hair ranges from 15 to 45 microns. Fiber artists generally chose from two types of alpaca fiber: huacaya (more of a crimp) and suri (longer and smoother). (Pic source)
I learned – the hard way – not to knit heavily cabled (adult) sweaters out of llama or alpaca. I was in a llama and alpaca stage at one point in my past, and knit two heavily cabled sweaters as gifts. The cables both flattened and stretched. Well, at least the sweaters felt luxurious.