> Like the cockroach of Ngerdobotar, staying on till it became white.
Presumably if a cockroach remains in the darkness for a long time, as one at Ngerdobotar (in Aimeliik) apparently did, it will turn white. Application pertains to a visitor who stays on and on, especially one who is not helpful in the household. Such behavior is not properly human; the person is somehow different, like a white cockroach.
