Crow will not become a stork by taking bathGenerally there is a sort of a phrase in certain languages meaning somewhat like this: "Crow will not become a stork by taking bath". In Malayalam it is stated as "kaka kulichal kokkakumo?" Crow is a black bird whereas stork is a white one. Both got the respective colors by nature. We use the phrase to indicate that a born criminal or one having very bad behavior cannot be modified as a gentleman through advises.
In the present world we have several examples to this. In every field we face people who never change their attitude even if forced. Advises will have no effect on them. Our political scene is becoming so filthy because of such people. Political parties also are not learning lessons from falls.