Why did a cry of terror come from the room from where the children slept in the birds?

In Daphne du Maurier's short story "The Birds," a cry of terror comes from the children's room as they are attacked by the birds that have suddenly turned violent and aggressive. This incident highlights the escalating threat posed by the birds in the story, as their behavior becomes increasingly menacing and chaotic. The children's fear symbolizes the loss of safety and innocence in the face of nature's inexplicable rage.