If your residence has trees around the premises... each morning as you awaken, you probably hear the sound of cheerful chirping of birds. It's almost like our little feathered friends are saying, "Oh God! It's morning!! (Yay)......"
Not like many people.... who say, "Ohhh, God(moan)...it's mornnning(groan)...."
Some folks might say, "Well, the birds don't have the problems I have...... so why shouldn't they be happy"?
But most of us don't have to go out and scrounge for our daily food....physically build a nest(home)......daily dangers with hostile birds, cats, b.b. guns, etc.
Remember....... birds are included in God's curse on His creation... and not because of any wrong they committed.
Romans 8:19-22, "For the anxious longing of the creation waits eagerly for the revealing of the sons of God. (20)For the creation was subjected to futility, not of its own will, but because of Him who subjected it, in hope (21)that the creation itself also will be set free from its slavery to corruption into the freedom of the glory of the children of God.(22) For we know that the whole creation groans and suffers the pains of childbirth together until now".
Maybe the birds are chirping = EVEN SO, COME QUICKLY LORD JESUS.