Alpacas are in general easy tempered animals. However, they are prey animals, and for the most part remember that they are just so-- although this doesn't deter alpacas from being friendly or loving attention, it does mean that they don't enjoy being chased, and may be stand-offish until they know you better and learn to trust you.
When scared, an alpaca will give a high pitched, birdlike "battle-cry" which sounds like a cross between a squeaky-toy and a bird. They are not an effective deterrent to predators, as they have few truly effective defences. Male alpacas may have fighting teeth (if they haven't been removed), which can allow them to try and bite predators, however the most commonly used defence tactic, is actually stomping and kicking. Because of their padded feet, they are overall of little threat to most larger predators.
It is a common fear that alpacas will spit. While all alpacas can and do spit, the vast majority reserve this pleasure for their fellow alpaca companions. Female alpacas will spit at male alpacas when they are pregnant, to tell them to stay away. Similarly, male and female alpacas will spit on each other when they argue or squabble over food, females, or unwanted intrusions. It is uncommon for an alpaca to try to spit on a human without a very good reason— the most common being mothers trying to protect their cria, or the animal themselves being put in a physically uncomfortable situation. Most of the time, however, any people that get spat upon have just ended up in the accidental crossfire of the alpaca, as it tries to spit upon one of its other herd mates.
With an alpacas small size, they are easy to handle, transport and manage. They can be trailer trained, or can be transported in a simple van or SUV. They are very smart, and can be taught to do a myriad of things, from basic halter/lead training, to being taught little tricks, to complete obstacle courses. There are even alpacas who pull small carts, or carry small hiking packs like their llama cousins. Their overall good nature make them ideal companion animals, and they are very good at "reading" the people they are around. They have a wide variety of hums and clucks, which can be used to tell the animals mood.
Alpacas are very clean, using a communal dung pile. The males will use their dung piles to mark territories, and tend to be a little neater in their pile formation than females, although this varies by animal.
Alpacas are very active during the day, and if the weather is kind, one can often see them "pronking" in the last few hours of light in the evening. Pronking is a stott-like gait similar to what mule-deer and antelope use, although this differs in that alpacas seem to pronk mostly when they are happy, not when escaping predators. One animal may start, and before long the herd takes off and many animals, young and old, will join in the game.
Young alpacas also seem to enjoy chasing each other in games similar to "tag". The males will often engage in neck-wrestling, most often for fun where they nip at each others ankles and attempt to overpower each other. Although startling at first, neck-wrestling is normally for fun. Adult males may take it more seriously, and will wrestle, chest-butt and nip if fighting for dominance, especially if open females are nearby that they can smell. Because of this more serious fighting, it is important to remove all males fighting teeth, to spare ears, testicles and other vulnerable parts from damage. Serious fights are uncommon.
Other things alpacas enjoy, include rolling in dust during the warmer months, especially after they have just been sheared. They will often roll and bask in the sun after being shorn, soaking in the sunlight for the short period of time when their skin is fibreless enough to get access to it.
Alpacas also enjoy water, and one must be careful that their alpacas aren't in a pen with a pond, as animals (especially cria) may wade in and drown. Sprinklers and spraying the alpacas with a hose on a hot day are safer alternatives, which they will appreciate immensely, especially when they have thicker fleeces. They love dipping their feet in puddles with the hose, or even being soaked down on their underbellies if they are hot enough. Our alpacas will often come running faster for the chance to play in the hose than they will for treats, and if allowed they would spend hours playing in it.