狡兔三窟 is formed by sequentially combining the characters 狡 (meaning cunning), 兔 (rabbit), 三 (three), and 窟 (burrow) to literally depict a cunning rabbit with three burrows. It originates from a Warring States period anecdote where this literal image was used to advise having multiple hideouts for safety. The phrase's formation directly constructs a fixed idiom that metaphorically implies the need for several escape routes or backups.