Final answer:
The question is a humorous statement about horse enthusiasts clucking at people to move.
Step-by-step explanation:
This question does not pertain to any specific subject or grade level. It is a humorous statement that refers to a common behavior seen in people who are passionate about horses. When someone says, 'You know when you are a horse person when you start clucking at people to move,' they are implying that horse enthusiasts may unintentionally make clucking noises to communicate with others, as they would with horses. However, it is important to note that this statement is not scientifically proven and is merely a lighthearted observation.