Insect Food containing protein, calcium, and Vitamin D3 to improve calcium levels in insects. Nutrogrub is a dietary supplement designed to feed insects such as mealworms, crickets, and locusts, which will be used as a food source for reptiles, birds, and other insect-eating animals. It is based on a delicious plant-based protein source rich in calcium and B vitamins, further enhanced by Nutrobal (our Best sellers calcium balancer) and calcium carbonate. Nutrogrub can be used dry, or you can mix it with water to prepare a paste for feeding insects. Replace it every 24-48 hours if used as a paste. Do not offer any other sources of water or Food during the 48 hours before using the insects as food for reptiles.