Frale Crimson

Frale Crimson, another name for Frale blood.
Humane are very reactive to the Dust and it's dangers, their blood grows duststone and deadstone, they are susceptible to being Fogworn, they attract Anz where as the Frale do not succumb to any of it.
While traveling in the dust, ancestors did not seem more aggressive towards travelling Frale compared to the Humane with them. When dead or duststone is exposed to Humane's blood it grows, and its the noise that attracts ancestors, as they do not track by following the scent of blood, but seem more alert about the noise of the growth.
Exposed Frale blood almost glows a rich crimson color, brighter than the Humane.
In the Dust Ancestors seem to be able to pinpoint the scent, and will track a Frale, endangering their own lives to approach the Frale. Numerous accounts tell different stories, from the Ancestor attacking or murdering the Frale and then disappearing back without causing havoc in the town, to attacking the Frale non-lethally, and the Frale faints, while the Ancestor dies, to the Frale riding or running out with the Ancestor never to be seen again. Sources can agree however, the ancestor only comes for the single Frale that was bleeding, and has no interest in anyone else.
Even safe within town walls and districts, Ancestors activity seems to increase near the Frale, though are usually safe from an attack.

One discovery does make their blood desirable for Dust Expeditions, it's attracts the Anz.
During Expeditions, a container of Frale Crimson is stored a breakable vial. Upon encountering and active Anz, the vial is to be smashed and used as a diversion for escaping. Without a Frale with the blood, it can only buy at most a minute, worst case a couple seconds, but that itself can be used to save an expedition and their lives.
Multiple vials can be broken if the Anz pursues the party, distracting the Anz They have been said to be angry enough at the sight of the crimson to continue endangering themselves in Dust Light to capture the Humane that tricked them.