The Bari are spaceborn insectoid aliens of rudimentary intelligence. Once on a starship, the small bari hordes begin to cultivate a fast-growing fungal mold for sustenance. Unfortunately, this mold dissolves and consumes most starship components with ease.
The bari tend to ignore humans in their horde state and cause no direct damage to the ship itself, but without fast action the fungal mold can quickly spread through a vessel, causing widespread issues.
If an infestation gets large enough without being removed, the bari hordes construct cocoons in which some of the horde metamorphose into bari warriors. These larger, bulkier insectoid creatures are hostile to non-bari life.
Eventually, if the infestation is not destroyed, a pod will be created somewhere on board. This pod will grow until it fills a significant section of the ship, at which point the bari will force the pod through the weakened hull of the vessel, allowing it to expand in space. This process is not clearly understood, but a bari pod can increase in size to several dozen times that of the ship that launched it very, very quickly. This expanded pod begins generating drone-like creatures that have been named 'spreader vessels', as they spread bari spores within the sector, infesting new starships to begin the cycle anew.
The only known threat to bari hordes and warriors are the creatures known as Felo, the only way to destroy a bari pod is via a plasma bomb.