Answer: nesting

AnswerCrossword Clue
NESTINGNidification
nestingthe act of making nests
nesting(of a bird or other animal) Use or build a nest
nesting(esp. in computing and linguistics) Place (an object or element) in a hierarchical arrangement, typically in a subordinate position
nesting(of a set of objects) Fit inside one another
nestingFit (an object or objects) inside a larger one
NESTINGLike some birds or dolls
NESTINGLaying laying foundations
NESTINGFitting one inside the other
NESTINGAvine activity
NESTINGFitting one within another
NESTINGAt home, as a hoopoe
NESTINGFledgling's delight
NESTINGFitting snugly.
NESTINGAvian activity.
NESTINGSpring activity in the avian world.
NESTINGBuilding a tree house?
NESTINGAvian activity
NESTINGUp a tree, perhaps