They just don't know what it is yet. It takes them a while. Offer them one thing at a time. When they decide they like it, offer something else. Once they get used to something they'll be wanting to take it out of your hands. Don't offer a smorgasbord until they (and you) know what they like.
my favorite hen Pebbles, an EE, and an incredibly good forager and very predator savvy hen hates sunflower seeds. She turns her beak up at BOSS and looks at me like I'm nuts. After a while she may eat a couple, or just walk away, often she jumps up on my arm and asks for something better. I admit Pebbles is spoiled and usually gets her way. LoL
