Other forms: empty nests
When all the children in a household have grown up and moved away, their parents are left with an empty nest.
A single dad whose youngest child leaves for college has an empty nest, and the phenomenon happens in most families: "My parents love their empty nest since my brother and I moved to New York!" The phrase stems from a psychological condition, a feeling of grief in parents whose children move on from the family home. Empty nest syndrome comes from the metaphor of a bird's nest after its babies have learned to fly.