the walls feature a quote from ireland's former president, mary robinson. >> after all, emigration isn't a powerful story of contribution and adaptation. >> reporter: centuries of giant contributions all coming from a small island. you know that thing your family does? yeah, that thing. someone made it a thing, way back in the day. but where did it come from? and how did it get all the way to you? curious? ancestry can help you find out. because that thing has a story, and it's still being written. what are you waiting for, a sale? well, lucky you. (vo) wish you knew how your cat was feeling? at the tidy cats innovation lab, we do! presenting our latest littervention. tidy care alert, with color-changing crystals for health monitoring. tidy care alert, only from tidy cats! >>> turns out some trolls get a bum rap, and lee cowan has proof. ♪ >> reporter: unlike happy-go-lucky leprechauns, whom we celebrate today, their close cousins, the trolls, are usually depicted in a less flattering light. ♪ ♪ >> reporter: ugly, brainless, with big noses and fat bellies. ♪ ♪ >> reporter: they are mythi