What causes paths on a hill to get deeper?

Paths on a hill become deeper due to a combination of factors, including erosion from rainwater runoff, foot traffic, and gravity. As water flows down the slope, it displaces soil and sediment, which can deepen and widen the path over time. Additionally, repeated use by people or animals compresses the soil, making it more susceptible to erosion. The continuous cycle of these processes leads to the gradual deepening of the paths.