The phrase "jumping on the bandwagon" describes the actions of a person who joins in a cause without really considering whether it is the right thing to do. As exemplified in this cheerful retelling of a classic fable for children, this may not always be the wisest choice.
Believing in a foolish superstition, Chicken Little is convinced that the sky is falling. In her distress, she convinces a number of other animal friends that this is indeed the case. One after another, the animals join Chicken Little, soon forming a frantic pack. Fortunately, Chippy Chipmunk steps in with wise intervention. What follows confirms the importance of critical thinking and the possible dangers of gullibility.