Vivariums In The Mist presents Iso Grub, part of its Advanced Isopod Nutrition line. Iso Grubs are freeze-dried minnows that will be consumed in their entirety, including the skeleton, which provides a needed source of calcium. In addition to isopods, the product is ideal for roaches, millipedes and certain reptiles. It comes in a 1-oz. resealable bag and makes a great addition to a balanced diet.