Lancer Beetle

The vile Lancer Beetle is the only creature that actually seems to thrive with the growing corruption of Zao. In former times a nuisance at best, the Lancer Beetles almost doubled their size and multiplied their dangerousness beyond compare. Within a few years, the vermin became a veritable threat. Campaigns to eradicate this pest by both, the orcs and the lizards, failed to bring a lasting change to the Lancer Beetle population.
Not really a swarm insect, Lancer Beetles usually live in small colonies. For unknown reason though, at certain times, they unite to build enormous swarms to devastate whole areas with their ravenous hunger. Guided by an unseen force, they crawl together even from the most remote spots. Without an apparent leader or queen, they seem to share a unique instinct and will to devour and destroy. Usually such swarms are met with resistance by the natives, and sharp battles for survival are fought against such swarms. Often enough, such fights can be compared with an attempt to stop a river with bare hands though. The sheer number of the beetles ready to replace one of their slain kin seems endless. However, after a while, as suddenly as it has formed, the swarm dissolves.