Additionally, cockatiels will eat grubs and different insects. Birds in captivity are less active and thus need less energy. However, like their wild brothers, they also require a varied diet. Cockatiels have been known to live around 30 years if given a healthy diet. I personally know of cockatiels that are in their mid twenties.
Seeds are high in fat and low in nutrition.
I have not found a pellet that my birds really like. I have also found that if my birds are on diets consisting of totally pellets, they tend to have more trouble with gout. I don't allow my birds to have foods which are high in sodium or sugar due to the possibilities of salt toxicity or health problems from sugar. My cockatiels won't eat a lot of fruits, but most of them will at least taste oranges, apples, kiwi, bananas, mangos, strawberries, and some melons. They also love cranberries.