Where is Daddy Duck?

If there are two objects (usually animals or people) or pictures and one of the objects is bigger than the other then Libby calls it the "mama". For example, last night she was in the bath and had three ducks - two small ones and a bigger one. The big one was "mama duck". (Funny enough, she knows they are mama but still calls me mimi.) Anyway, I asked her were the daddy duck was and she let out a loud belly laugh. I guess that was a stupid question...
TLA