Bluebird finally decides it's had enough of a wasp sharing its nest

Wasps sometimes build their nests in the same boxes at Eastern Bluebirds. We were watching today as a wasp came and went, apparently planning to build a nest hanging above the bluebird's nest while she incubates. Would she do anything about it? We got our answer after the wasp found its way to a lower corner of the box and she disposed of it.