I bought some plastic eggs, put treats inside, and placed them around the living room this morning. I've hid treats this way before, which Riley enjoyed, but he didn't particularly care for the eggs. He sniffed out a couple, but he doesn't usually pick things up and even walked away from the second egg. I opened those two and gave him the treat. Then he gave up and went and sat on the couch - right on an egg that was hidden in between the cushions! So I gave that one to him, too. Sadie found the other 9 and carried them around (typical Lab) for me to open. Then she learned to open them herself. She had a great time!
Here are some pics of the hunt, their rawhide afterwards, and of Presciosa, my neighbors' dog, who has been undergoing heartworm treatment at my house for the past 5 weeks or so (almost finished!):