Fly the Coop

Etymology:

• The word “coop” in this expression is a cage or hutch to keep small animals or poultry. A chicken was said to “flew the coop” when it escaped or fled its stockade. It is to be noted that “coop” was used as a slang word in late 19th and early 20th century for jail. The expression was much used for prisoners who got escaped from jail. Today the phrase can be associated or linked with any person or animal who secretly runs way or escape from place or pen.