How do ducklings fall asleep‪?‬

In this story, Alexandra gets to know how ducklings sleep. She is camping with her mom in the Swedish archipelago. One warm, autumn evening in Sweden, nine-year-old Aleksandra went to the coast. "The weather is so nice," her mother said, "we'll take our tent and camp for the night."
Aleksandra had only slept in her own bed before. She wondered if she'd be able to sleep outdoors...