As a matter of fact, there was.
Bert stares at his plate of cookies, and sees they have been taken. So he yells at Ernie to come in, expecting Ernie to know why he's mad, and Ernie has no clue. He explained to him about the word "cookie", and then Ernie gets his great big plate of cookies, and Bert yells at him for picking up the cookie, about to eat it, because they're BERT'S cookies. And then Ernie says they're his cookies. And that Bert's cookies were on the empty plate. Well, they WERE, but there are clues that we can examine to find out what happened to MY cookies. And Bert says that if someone with a red and blue striped shirt, a tuft of black hair on top of his head, and someone who laughes "keeheehee" took cookies off the plate, it would mean that Ernie had come and taken the cookies. But then Ernie admits that he didn't take the cookies. And Bert doesn't believe him. Then, Cookie Monster, dressed exactly like Ernie, takes Ernie's plate of cookies.