Best Brand in UK Why are mealworms a good bird food source? Mealworms are a rich source of protein (over 50%), fibre and fats that are key for muscle development in birds. Though high in protein they are low in calcium and should not be the only food you leave out in your garden. Any insectivorous (soft billed) bird will love mealworms. The majority of passerines (perching birds) will enjoy them too, especially when they are feeding their young & the protein is essential for their growth. Packaging & Ingredients Packaging Chubby Mealworms are packaged in a resealable plastic container or a plastic resealable bag, depending on the size that has been ordered. This ensures your mealworms stay fresher for longer. Remember that the bigger the pack of dried mealworms you purchase the cheaper the price per Kg becomes. Typical Analysis Just 100% natural dried mealworms.