Frightening Birds

When we change something in our bird house, if we observe birds closely when they come back.
We can see that birds are rather frighten and are hesitate to go inside the bird house.
They will take time in circling around and around the bird house before they finally flying inside.
When they are inside, they still fly in a very chaotic way and take time in each room before they fly further to each deeper room inside. So best is not to change thing too often, they need some times to adjust themselves for each change we made.