(Note: I'm using the modern English version of the poem "To a Mouse")
The title of John Steinbeck's Of Mice and Men is an allusion to "To a Mouse," a poem written by Robert Burns, who lived during the 18th Century. In this poem about a farmer who turned up a mouse's burrow while ploughing Burns writes, "The best laid schemes of mice and men, / Go oft astray, / And leave us nought but grief and pain, / To rend our day."
These lines alone should provide some connection to Of Mice and Men. Each character presented in the book has some type of dream he or she feels destined to reach. For George and Lennie, it's owning that ranch where Lennie can take care of the bunnies. For Curley's wife, it is going to make movies. But for every character, there is a dashed dream. Their "best laid schemes" went "astray."