Where do birds get their eggs?

That was the question of the night. I knew what Ben meant, but I played dumb. I said, "they lay them Ben." "I know mom, but where do they get them?" "Well Ben, the mommy and daddy make them together." "Oh, that's so cool, a mommy bird makes her own eggs." At this point the subject changed and he wanted no further explanation. So, if any of you wants to talk birds and eggs with Ben, he can give you the low-down according to him and what he "heard" me tell him.