Play with me

When our girls were small we played a game,' which does not belong.'
You know , like, apple, orange and egg.
Well on my walk tonight there were three things. See if you can tell which one does not belong:
A dog, a cat, and a rooster.
Yes, where did that rooster come from? No one seems to know. The last time I saw him ,he was, you guessed it, crossing the road!
Want to play again?
Which of these does not belong?
Joy, peace and worry?
More on that tomorrow.