I found something strange in the countryside. what could it be?

Irecently i took a walk in the countryside. I loev nature - i find it so peaceful. after a while i came to a lake which i had not noticed before, and which impressed me a great deal. The banks were lined with flowers and i also noticed some swans. Now my question - i get the feeling that these were not real swans but girls who only regain their human form at night. Could this really be the case? thanks Arthur