Gone Home: How to Find All Hidden Trophies/Achievements

Nesting Instinct (Silver/50g)
Returned Christmas Duck to his rightful place.

Remember that duck from the very beginning of the game? Once you unlock the attic, go back, grab the duck, and bring it up with you. As soon as you go up the stairs to the attic, turn around and you’ll see what looks like a nest.

Place the duck in it, and this will unlock.