According to experts, poison prevention, like most areas of safety, must be taught at an early age. Marcie Evans, 2, shows her understanding of the meaning of Mr. Yuk and his relation to potentially dangerous household items in March 1975. Marcie, her mother, Mrs. Patrick Evans, center, and Mrs. Dorothy Kriley of Prescription Pharmacy look at the Mr. Yuk stickers. The stickers and charts were given free to parents at all Butler County pharmacies.