Wit? Lathe? I'm afraid a moth is capable of more wit. Or maybe more or less the same level of intelligence, actually, as Lathe seems drawn by the glow of the orb. Though that's hardly surprising given that his sister controls all the light he's seen before.
Well, fear and Lathe go together terribly, so he'll have no qualm about touching a obviously magical, possibly dangerous orb. After all, it's glowing. How bad can something glowing be?