I've been working on a new pet character, and just recently ran to rats to fill a bundle for appraisal. I was surprised when skinning rats was teaching at 109 ranks. Log below:

Your formation of a targeting pattern around a ship's rat has completed.
> sk skin

SKILL: Rank/Percent towards next rank/Amount learning/Mindstate fraction
Skinning: 109 20.99% thoughtful (4/34)

Time Development Points: 800 Favors: 0 Deaths: 0 Departs: 0
Overall state of mind: clear
EXP HELP for more information

> cast

You gesture at a ship's rat.
A crackling stream of energy flies at a ship's rat!
A thick splatter of blood explodes from its vanquished right eye.
The ship's rat falls to the ground and lies still.

Roundtime: 1 sec.

R>
The ship's rat closes to pole weapon range on you!
> skin

With preternatural poise, you work loose a sterling example of a rat pelt from the rat carcass.
You carefully fit a rat pelt into your bundle.
Roundtime: 2 sec.
R> sk skin

SKILL: Rank/Percent towards next rank/Amount learning/Mindstate fraction
Skinning: 109 20.99% thinking (5/34)

Time Development Points: 800 Favors: 0 Deaths: 0 Departs: 0
Overall state of mind: clear
EXP HELP for more information

Takes about 4 skins to move a mind state. Was able to make it to 10/34 before I stopped. Tactics which is way lower didn't move so definitely something with skinning.