Why does pepper move away from soap

i want to know why this happens? but i need i really simple explanation! like a third grader would understand ! i'm doing this experiment about the pepper moving away from the dish soap :)
thx :)

Water has surface tension. You can see this where the top of the water meets transparent glass and curves. It's like a natural skin over the entire surface of the water, though. Soap breaks that tension, like popping a bubble but in slow motion. As the hole of low surface tension gets bigger, the skin of higher surface tension pulls back and carries the pepper with it.