The smell of crayons - one of those scents that instantly takes you back to your childhood years. But have you ever wondered what makes crayons smell they way the do?

What you may not know is that unique odor is actually created in large part by what's called "stearic acid", which is a derivative of beef tallow, more commonly known as beef fat. That's what gives each crayon its waxy consistency.

Always looking to offer variety, Crayola released a line of food-scented crayons in 1994. Dubbed Magic Scent, they came in coconut, cherry, and licorice flavors. But by July 1995, Crayola had taken them off the market. Parents feared kids would eat them.

Rather than doing away with Magic Scent all together, the company instead changed the scents to be less appetizing. Brown, for example, went from smelling like chocolate to smelling like dirt. Because “kids love dirt,” a company spokesperson said.

In 2006, the company launched a line of Silly Scents crayons and markers intended to appeal to the Garbage Pail Kids demographic. One crayon was actually dubbed the "Booger Buster"; another was called "Alien Armpit."

(Source: Mentalfloss.com)