Grubs are the young of beetles, which may also be known as the larvae. The young are usually born into a gallery that is located in a plant or tree with some form of food nearby for the young so that they can develop. This food usually feeds the adults and the grubs, and the adults stay with the grubs until they develop into adults. The grubs especially enjoy fungi or moss, and don't eat their host plant. In some parts of the world, a grub make a great snack for school kids just like you!