Unusually among voles, in addition to storing food, such as roots and rhizomes, underground, singing voles also often leave stacks of grasses out on rocks to dry. Often, these stacks are instead constructed on low-lying branches, or on exposed tree roots, helping to keep them dry. The stacks of grasses slowly dry out, producing hay, and may include other food materials, such as horsetails or lupines. The voles begin to construct the stacks around August, and by the winter, they may have reached considerable size, with piles of up to in height having been reported. The piles are a source of nutritious food through the winter, although they are liable to be raided by other animals.