Where Does Your Egg McMuffin Come From? An undercover investigator for the animal rights group Mercy for Animals worked at different egg farms run by Sparboe Farms in Colorado, Iowa and Minnesota for three months earlier this year. The investigator, "Scott," shot undercover video footage at the facilities that Mercy for Animals says shows unsanitary and inhumane conditions. Sparboe Farms is the country's fifth largest egg producer. Courtesy of Mercy for Animals