Our broad and scientific study (giving frogs at random to people of all ages) has proven that folded frogs are fun for folks aged 3 to 100. Children under age three usually lack the dexterity to push the spring-fold at the tail of the frog to make it hop. Instead, they tend to smash the frog flat. They may like to see it hop, under the impetus supplied by mom or dad, but they lose interest fast.
Often, the parents who receive frogs for their kids enjoy them as much or more than the children. Adult eyes light up, too. If Don has made a frog but the children have left the restaurant before he can bestow it, he will hand it to whoever seems a likely recipient. Elderly women are especially overjoyed to get them.
If the frog you got from Don at a Starbucks in southern California got squished on the way home, you can click on our Frog Folder tutorial on YouTube and make another. Heck, you can make a dozen, or a hundred, or a thousand!