Inspired by the Flickr group ID Please, this is a place to post observations of things you don't know, and to help people identify mysterious creatures!
It looks like a potter wasp, but it is outside a nest made in an old carpenter bee hole so not a pot type nest. It is about 1cm in size. A male waiting for the females I suspect.
first picture is of the two mother ducks, although doesn't look like it here they are beginning to have territorial struggles. The five ducklings of one of them are little and when they wander into the territory of the other family, their mother tries to drive the other family off. Guess they will work it out. Initially they each had a side of the bridge but the little ones have no concept of such boundaries.