Rakaans were hunters who caught prey in the webs they spun from their abdomens. These webs ordinarily lasted two hours before losing strength, but Rakaan saliva mixed with juices produced a preservative that allowed them to last for weeks, and other glands in their mouths produced a substance which dissolved them. Long-lasted webs were used to cocoon prey for later feeding. In combat, Rakaans could shoot their webs, or bite with their fanged mandibles.
Rakaans were born from eggs. They began their lives in a child phase, which lasted thirty years on average. In some cases, Rakaans would spend only five years as children, or spend sixty years before maturing. Rakaan children were only half a meter tall on average.
At childhood's end, they went through a period called the "Transition". At the end of the Transition, a Rakaan would end up one of four sexes—male, female, neuter, or "andro". The balance of the different sexes depended on the conditions of a Rakaan community. During periods of famine, more Rakaans would be neuters. When the Rakaan population was in decline (during a hive war, for example), more Rakaans would go through the Transition to become male, female, or andro to increase breeding rates. Over a 160-year lifespan, Rakaans would go through the Transition several times. On average, a Rakaan would go through at least three Transitions, spending anywhere from three months to eighty years in one sex. During the Transition, Rakaans were often violent and ravenously hungry.
Rakaan males were about two meters tall, and had keener senses than other sexes. Females were the largest Rakaans, standing up to three meters tall. They also had an elongated abdomen, where they could carry and nourish fertilized eggs for three months. Afterward, they transferred their eggs to nesting chambers, where andros cared for them. Andros moved more slowly than other adults, and had the ability to produce a nourishing paste which they spread over the eggs. The last Rakaan sex, the neuters, took no part in reproduction. Instead, they were the guards, hunters, and warriors of the Rakaan community. Being only 1.5 meters tall, and having a more efficient metabolism, their food requirements were less than other Rakaans.
Rakaans were rarely away from their homeworld, despite its central location in the galaxy.