and enter into their baths, and it is said that the baths that a enters in would get dirty with grease floating in them as well as a very foul odor. and other strange events in the mountains are often considered to be the deeds of mountain gods or in the Eastern half of Japan, but in the Western half they are considered to be the deeds of . Phenomena such as the (sounds such as that of a large tree falling) are considered to be done by the themselves, and in the Kumamoto Prefecture, other than stories where they would make falling tree or falling rock noises, there are also stories where they would imitate human songs and where they make sounds imitating (a tool made of bamboo or woven grass for carrying heavy loads) dropping dirt or even the explosion sounds of dynamite. However, the does not play no role at all in those regions, because in some parts, such as the Oguni in Kuamoto Prefecture, there are no legends and they are instead considered to be the deeds of . and migration In various places in the Western half of Japan, there have been confirmed to be legends where are that have moved into mountains. In many of them, would move into the mountains during the autumn Higan to become , and during the spring Higan they would move back to the rivers to become . Kumamoto Prefecture: would move to the mountains during the autumn Higan to become and would return to the rivers during the spring Higan to become . Kuma District, Kumamoto Prefecture: and would switch with each other every February 1 (called the ) Minamata, Kumamoto Prefecture: On , would go from the mountains into the rivers. Wakayama Prefecture: would go into the mountains to become in the autumn and would return to the rivers to become in the springtime. Yoshino Region, Nara Prefecture: would go into the mountains to become during autumn Higan and return to the rivers to become during spring. The folkloricist Kunio Yanagita theorizes with words such as "river-child migration" that these seasonal changes between and comes from the seasonal changes between faith and the field gods (Ta-no-Kami) and the mountain gods (Yama-no-Kami) and that since birds could often be heard in many places during those times, it may be related to the bird migrations that happen with Japan's