Rat candy is rodenticide. The name is a slang nickname, the exact origins of which are not conclusively known. One possible origin is the way that a rat is attracted to rat poison like a child to candy, another possibility being the use of actual candy, particularly chocolate, as bait when luring a rat into a trap that will lead to its imprisonment or demise.[1]
According to United States Environmental Protection Agency statistics, approximately 13,000 American children were treated for ingesting rat poison in 2004, most mistaking the rodenticide for candy.[2]
Warfarin, an early rat poison, was derived from licorice. Tales of poisoned candy also abound in urban legends.