Violet-Green Swallows Feeding

The chicks are putting their heads out now as their parents swoop in and swoop out. I've been observing these Violet-Green Swallows for quite a while now. They seem to have to chase off other Swallows pretty often. One of the parent is on look-out much of the time too. Maybe he's resting! They are a very hard working couple though. They swoop in and out, non-stop all day long. One chick seems to capitalize on the opening to the house, I don't really see the one ever move!