I've had really good luck breeding isopods. I'm not sure how much they would cost because I had a school science kit coupon for some. You put some peat moss in there, cover it with dehydrated moss from a pet store, add water to make it all moist, and they will love you forever! They eat pieces of potatoes, and they eat the moss itself. They live on decaying matter, so it's up to you what you want to put in there. My beardie ate a few and I would feed him those when he was out of crickets. They weren't his favorite as a baby. I haven't tried them with Tweety yet. Perhaps she'll like them too. They are seriously easy to grow. They reproduce like crazy.