Vermin

Chirska: The small vermin of granaries, stores, and walls, and the most common pest in the world: small, quick, prolific, into everything, defeating every trap, breeding faster than anyone can kill it. Every household deals with it, every store budgets for it, every city is haunted by it. It is the reason Neska are kept. Chirk is the thin scratching squeak a Chirska makes inside a wall — the warning before the damage — and a person who says they heard chirking has given the household something it will act on the same day.
Tyvra: A small nimble climber of yards, hedgerows, and rooflines, up a wall before anyone has finished noticing it, with a ridge of short bony spines down its back that lie flat and rise when alarmed. It takes unguarded Chichei, raids Nywich hives for comb and grub, and eats nearly anything. Universally cursed, more nuisance than danger; everyone who keeps a bird has lost one to a Tyvra and has a theory. It is native and was never a target of anything; it is abundant now because its competitors are gone — the ground hunters of its size did not survive, and the Tyvra did by hiding in trees.

Hidden truth — not known in Teraell

The Chirska was engineered as a food-denial weapon to destroy enemy grain stores and released into enemy territory, alongside the Rhydda for standing crops and the Fellwyr for livestock. It has naturalized so thoroughly that nobody thinks of it as anything but a pest.

See also