Baby swallows leave the nest
These Barn Swallows have already fledged from their nest, but the young of the species is led back to the nest by the parents to spend the night for several nights after they fledge. They are so large, basically adult size (though their tails are shorter than on adults), they barely fit back in the nest. The bottom pic shows the empty nest with all the feathers that the parents collected to make a soft nest lining. SeEtta