You may be familiar with ferrets, those adorable little mammals that look like cheap minks. Well, the verb to ferret means to act like a ferret: to dig for something until you find it.
Ferrets are great at digging, so it's no surprise that we acknowledge their skills when we make the verb ferret, which almost always comes attached to the preposition "out." Woodward and Bernstein worked tirelessly to ferret out the names of the guys who raided the Watergate offices. When you're ready, I'm going to ask you to ferret out those two photos from that stack of photo boxes.