In lunfardo rioplatense it is used as "lazy, do nothing productive". The origin is not clear, it is supposed as a variant of the irony "to be scratching the eggs" (without fulfilling obligations, taking care of the male of his own testicles), which can even come from an antiphrase for a misinterpretation of "do not scratch ball"; although for contadictio we can trace an old phrase "do not make uebos" ("not to do what is necessary") that was refloated at the end of the eighteenth century and then fell into oblivion, and that phonetically comes closer.