Herd behavior is a phenomenon in which individuals in a group act in a similar way, often following the actions or behaviors of others in the group. This type of behavior is often seen in animals, such as birds or fish, but it can also be seen in humans. Herd behavior can have both positive and negative effects, depending on the situation. For example, it can lead to increased efficiency and safety in a group, but it can also cause people to make irrational or dangerous decisions.