Scribble is random movement of a pen or pencil on paper while a doodle usually has some method about it. Doodling consists of simple or abstract pictures while scribbling is chaotic and disorganised. Also, in some parts of the world "doodle" is a name to describe a boys private part.

I SCRIBBLE words (untidily, hurriedly, in ink or with a pencil) but I DOODLE pretty little patterns and drawings (slowly, artistically!). Scribbling is writing (even if it is hard to read!) and doodling is drawing.

About 10 years...