Newswise — Feb. 28 is National Tooth Fairy Day. Elizabeth Tucker, disginguished service professor at Binghamton University, State University of New York, is an expert on children's folklore and has some insight on the holiday's origins and more.  

"The tooth fairy originated in the concept of giving a child a gift in exchange for a lost tooth, which has its earliest expression in the Icelandic Eddas," said Tucker. The Eddas were written in the 13th century. 

"Sometimes an animal is said to take the tooth: for example, Mexican parents may tell their children to expect a visit from the tooth mouse." 

Tucker added that the rate of exchange for a tooth has gone up over the years. 

"In the 1950s in the USA, children hoped to get a dime or a quarter; these days, children may expect to get a dollar or more," she said.