Answer:
Expansion and contraction of rocks
Step-by-step explanation:
As the temperature increases the rocks will expand as per law of science. When night falls the rocks will cool and contract. The smaller differences in daytime and nighttime temperatures are not enough to cause any significant changes. However, with increasing daytime temperatures and decreasing nighttime temperatures, the temperature difference is great. This causes, a larger expansion and a tighter contraction. This constant expansion and contraction eventually creates cracks in the rocks that become larger and may propagate deeper into more rocks.
This scenario is also true for changing seasons between winter and summer. Hotter summers and colder winters mimic the expansion and contraction for night and day temperatures.
Constant cracking will eventually lead to weakening of structures and eventual breaking and eventual falls. This is a dangerous occurrence for animals and people in these areas and caution must be observed for "falling rocks".