Denny's is the latest breakfast chain to charge extra for orders containing eggs, an ever-costlier commodity in short supply due to the killing of millions of egg-laying hens as a result of bird flu. The restaurant said the additional and temporary fee will vary by region and location. The move by the Spartanburg, South Carolina-based brand comes weeks after fellow breakfast chain Waffle House added an egg surcharge. The 70-year-old Denny's brand involves 1,499 restaurants, most of them in the U.S. and run by franchisees, according to its website. The company said it attempts to plan ahead "to minimize the impact market volatility has on our costs and menu pricing," but still has to charge more given the nationwide egg shortage and increased cost of eggs, the company said in a statement.