Each month's full moon has its own distinct name. And for March, the most common name is the Full Worm Moon. It can also be referred to as the Full Sap Moon, given that the end of winter/early spring is when sap begins flowing in maple trees.But the Full Worm Moon is called so because it falls during a time of year when the ground is beginning to thaw, and earthworms start resurfacing after the cold winter. As such, this moon is all about the advent of spring.