I was digging in the soil near Hemlock and Yellow birch trees and happened upon these deer truffles, or Elaphomyces species. These are hypogeous fungi, meaning they form their fruiting bodies beneath the leaf litter. Although in the same phylum, these are not the same genus as the gourmet cooking truffles that more people They rely on mammals to dig them up and consume them, dispersing their spores in the feces of the mammals. Some small rodents, such as the Northern Flying Squirrel, rely heavily on fungi in their diet. These same fungi also form relationships with the surrounding trees, helping the roots of the trees to have increased surface area to absorb nutrients. In return, the fungi get a source of carbon (sugars made in the trees' leaves) for their energy. This type is actually fairly common, but most people don't see them because we don't go digging in the dirt in forests very much.