gelatin, actually. I think I would not want to use the dessert gelatin with food dye in it....but what about unflavored/uncolored gelatin? I give my girls frozen peas and beans, and I've seen photos on the internet of people making ice cubes with treats inside.....but my girls don't like ice! And won't it hurt their beaks? Anyway, what if I used the gelatin with little veggies or fruit inside? It would be cool (not as cold as ice) and nutritious. Whaddya think?