Also available on AO3.
Caleb doesn’t have an Itch like Nott does, not exactly.
There are things he wants, obviously; there are things he’s stolen because he’s wanted them or needed them, taken when maybe it wasn’t the best idea, or the smartest time. He doesn’t feel a compulsion, though, it’s not the same.
That’s not to say that sometimes- not often, but sometimes- he has needs.