noun
changing nests; moving to a new nest
Used for birds or other animals that relocate to a different nest. Often implies seasonal or breeding-related movement.
ツバメが巣替えをする時期になった。
It's the season when swallows change nests.
noun
changing one's place of entertainment; moving to a different pleasure spot
Rare, old-fashioned term for moving from one drinking or entertainment establishment to another. Modern Japanese would more commonly use はしご or 場所を変える.
昔の遊び人は、夜な夜な巣替えを楽しんだという。
It is said that old-time pleasure-seekers enjoyed changing their place of merriment night after night.
Common modern term for bar-hopping or moving from one drinking place to another. 巣替え in the entertainment sense is rare and old-fashioned.
Compound of 巣 (nest) and 替え (changing, from 替える). The literal meaning is 'changing nests'; the rare entertainment sense is a metaphorical extension.