The scavenger mite is a scourge of the traveller in orc lands. They are not natural creatures, instead they were once ticks, lice, and fleas who gorged themselves on the blood of orcs. Since orcs spend so long on the campaign, it's common for them to develop these pests, due to grueling marches and being whipped bloody and raw. However, it is not these pests that become blood scavengers. These pests will sometimes end up in the hair and clothes of an orc used in a ritual, or, much more rarely, on one who has drunk of the dark themselves. These will taste of the Dark Blood themselves, and lack the will to resist its call.
Being mere insects, these dark blood gorged insects start to breed as grow into swarms of pests. These can be any of the tiny biting insects, and it's rare for a swarm of scavenger mites to be a single type, but they are collectively called scavenger mites anyway. They can grow quite large, but are still only about the size of a sheep's knucklebone, though such large specimens are rarely the greatest threat, even when they grow to swarms of dozens of giant mosquitos (tales tell of swarms of thousands destroying whole towns though). The true horro of the scavenger mite is not that they have a taste of orcish blood, it's that they don't. The scavenger mites want the pure divine blood of dwarf, elf, and man.
The scavengers begin to swarm around those who survive battles with the orcs. The smallest of the mites will attach to these survivors, burrowing into clothes, attaching into shins or ankles, and trying to lay broods where these sources of blood stop. These camps, infested with mites, spread far and wide, bringing the mites away from orcs. These mites then become horrible problem for the peoples who receive them. They poison the fields, filling pools and other ways, they poison any sources of rot, especially crops rotting in the field, and they poison people, living in their flesh until they can afflict them with horrible diseases.
The most powerful of the mites can eventually even learn to walk along ley lines and other sources of telluric energy. Most mites are only three to four times larger than an ordinary insect, but some of them begin to swell with the horrible energy of the dark blood. As they swell they can become a major source of dark blood. These the orcs will seek out and, where possible, consume in order to strengthen their rituals. Many will see these orcish skewers covered in giant bugs and see horror, but orcs will consume these giant bug corpses as a way to empower their horrible rituals.
Scavenger Mites are not a traditional monster. They exist primarily as a horrible creeping dread, things that grow in the clothes, water, and skin of those who live nearby. Scavenger Mites need to be held under control before they becomes a problem in a camp. If the camp has a dedicated doctor, they can make an Ob1 Field Dressing test to become aware of Scavenger Mites who have only just been brought into camp as they perform their routine duties. If the camp doesn't catch the mites in their initial disease management, then anyone watching the stores or the soldier can make an Ob 3 Soldiering test or an Ob 2 Observation test to notice the strange mites.
If these tests are failed, the mites will cause a superficial wound to anyone in the camp, and these people gain a +1Ob to all health tests. Once this begins, the camp members will begin to notice the welts and bites, or even large burrowing insects in their skin. These can be brought under control with an Ob 3 Herbalism or Apothecary test (this is taken over three days). If this fails, the penalty to Health tests, and the Ob on the Herbalism and Apothecary tests, increase by one every three days. As usual, curing a superficial wound requires a Health test to clear the cobwebs, so the daily superficial wounds will quickly add up. While the scavenger mites are not managed, roll once a day to attempt to recover from each superficial wound, until it becomes light and must be properly treated. Camps infested with mites must have skilled doctors to prevent being overwhelmed by these mites and being destroyed.
Scavenger Mites who have become endemic to an area, properly feeding upon an entire camp, and being brought close enough to a permanent steading to be able to feed, they begin to grow large and engored. These mites are often easier to spot, but more stealthy in the manner. They are Ob3 Soldiering or Observation to notice in low brush or stagnant water, and an Ob5 Apothecary test to remove once they have latched on. If this apothecary roll fails, they can be remove by jabbed a white hot stick into the embedded bug, dealing a B6 wound. Otherwise, the mite will deal 1D Forte a day until someone removes it. If the mite drain 5D Forte, it explodes in a swarm of mites and they attach to all nearby (Soldiering or Observation to prevent, Apothecary to remove as above).
If some with the Void Embrace emotional attribute decides to eat these mites, they can do so easily. In order to keep the mite vital they must consume flesh around the mite, dealing at least a B5 wound as part of the consumption of the mite. When they do so they gain +1D to any rituals of Night or Blood roll per mites consumed.
A Burning Wheel Monster Every Week