1º_ It is another of the common names of the machaca insect (Fulgora laternaria), which in its adult phase develops a large head similar to a peanut or peanut pod as a method of protection against predators, because there it has two spots that resemble eyes, which combined with the colors of the wings gives it an appearance of small reptile. See jupa ("head"), butterfly caiman, chicharra-machacuy, cocoposa. 2º_ It is a variant of "hollow head" ("irresponsible person, who does not meditate what he does") that is used more as a "peanut head".
