Wrens have a tough time making up their minds

Carolina Wren

Wrens in nest bottle

Before selecting a mate, a male Wren locates four or five possible nest sites, and seeds each of the areas with lots of sticks and other nest-building materials. Then he chooses a mate. The mate/female then chooses the best nesting site and builds the real nest, using the materials put there by the male.

She'll lay 4 to 8 eggs but, like all birds, won't begin sitting on them ("incubating") until the last one's laid.  That way they're all hatched at the same time.

CLEVER BIRD: