There is a theory about why dogs fight on the moon. Typically, they decided to climb it and began to build a living staircase, one dog jumped on the other, and so on. One of the lower dogs could not withstand and broke. The entire staircase has collapsed, and since then the dogs have walked around the Earth and smelled each other under the tail - looking for who has stumbled, and fought to the moon in memory of the unfulfilled dream.