What do Unicorns, Bald Eagles and Shamrocks have in common?

Why is the Unicorn the National Symbol of Scotland? Why do we have National Symbols? Which animal represents the most countries? For free home activities sign-up at www.WhoSmarted.com See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.