New swarms are created when a swarm becomes too large to be supported by the area of river in which it lives. A number of the bandaras will break away, floating downriver in a large mass, until they land on an empty sandbar.

Bandaras do not actively hunt, subsisting instead of whatever detritus floats their way in the currents of the Devaronian rivers. They find great success with this apparently ineffective method of feeding because they are able to eat almost anything. They use their strong mandibles (combined with the sand on which they live) to reduce many varied types of matter to its constituent elements and then extract whatever organic material is available.

Because of this, Devaronian river pilots are extremely careful when navigating in the vicinity of a sandbar occupied by a bandara swarm since any boat that runs aground on such a sandbar will be quickly consumed.

Though the female Devaronians claim that the bandaras pose a danger to their planet, they are, in fact, little more than a nuisance. While it is true that their voracious appetites have been responsible for the destruction of valuable property, and that riverways have been forced to close due to infestations of bandaras, these are only isolated incidents. The true reason why the female Devaronians have such a great dislike for bandaras has more to do with their mating behaviors than it does with their appetites.

During the Devaronian summers, the male bandaras attempt to prove their worthiness for procreation by "singing." They produce their song by vibrating the long, narrow auracarpal that grows from their backs. These songs can reach volumes of over 160 decibels and range in frequency from 110 kilohertz to over 30,000 kilohertz. A swarm of singing bandaras creates an oppressive drone that most sentient beings find unbearable. Male Devaronians are one of the few groups of beings known to tolerate the noise, and it has been conjectured that they even welcome it because it so greatly annoys the female Devaronians and helps to keep the females away from the rivers of which the males are so fond.

The females of Devaron have expended a great amount of energy in their attempts to rid the planet of bandaras, but they have been unsuccessful. Bandaras may be freely taken off planet (and, in fact, during some seasons, taking a cargo of bandaras off planet entitles a trader to a reduction in tariffs), but any being caught bringing bandaras to Devaron is imprisoned in a small cell for the remainder of its natural life.

While it is well known that the female Devaronians are trying to rid Devaron of bandaras, there are rumors in the smuggling and trading communities that the male Devaronians have spent almost as much energy in trying to save the bandaras.