What is the figurative language device used when saying "I'm as busy as a bee"?

The expression "I'm as busy as a bee" employs a simile, which is a figurative language device that compares two different things using "like" or "as." In this case, it explicitly compares a person's busyness to that of a bee, which is famously known for its industriousness and constant activity. This comparison helps to vividly illustrate the type of busyness the speaker is experiencing.

While idioms might also convey a similar sentiment, they do not follow the comparison structure that similes do. An idiom typically represents a phrase whose meaning cannot be easily understood from the individual words, whereas a simile directly makes a comparison and retains the meanings of its components. This distinction reinforces why “as busy as a bee” is categorized correctly as a simile.