behave vs muck about

behave

verb
  • To act in a polite or proper way. 

  • To conduct (oneself) well, or in a given way. 

  • To act, conduct oneself in a specific manner; used with an adverbial of manner. 

muck about

verb
  • To be playful; full of fun and high spirits; to not treat the situation seriously. 

  • To do random unplanned work or spend time idly 

  • To attempt to do something with a piece of equipment without understanding how it works. 

How often have the words behave and muck about occurred in a corpus of books? (source: Google Ngram Viewer )