Breakfast cereal could use a lucky charm. U.S. sales of the colorfully packaged morning staple have been in a decades-long decline, a trend back in the spotlight with news that Italian confectioner Ferrero Group plans to purchase WK Kellogg, maker of Corn Flakes, Froot Loops, Rice Krispies and other familiar brands. Except for a brief period during the coronavirus pandemic, when many workers were home and had time to sit down with a bowl of cereal and milk, sales of cold cereal have steadily fallen for at least 25 years, experts say.