While they will not attack Talion nor the Uruk army on sight, they will become frenzied when their nest is disturbed. Cutting a hive from its supports or using Azkâr to shoot one down will result in scaring away all common Uruks, as well as triggering a Nemesis' fear or hatred of them.
With Mordor's predilection for leaving the recently deceased without a grave, Morgai Flies have become a mainstay throughout the region. Their nests can be found hanging anywhere there might be flesh to be had, and any disturbance to these nests sends the insects into a frenzy. When this happens, the malevolent creatures swarm, working in concert with one another, creating a relentless, stinging mass powerful enough to overwhelm even the most heavily-armored Uruk.
The red markings on their back are reminiscent of the blazing Eye of Sauron, suggesting that these creatures are extensions of his dark spirit.
- Morgai Flies are also featured in The Return of the King where they appear to be the only wildlife in Mordor at the Time.