Duck, Part 2

On March 23, I was graced with the presence of a duck in the house. As I walked past the study today, what did I hear but flapping of wings (it sounded like the poor thing was in a panic). Yup, another duck. He ran around the house and I finally caught him in my mom's closet. Every window on the front of the house was open, but he went out through the door -- I picked him up (in a towel) and set him on the front porch. I don't understand why they keep coming back. Our house is not built for ducks.