Dragon dances had appeared by the time of the Han. People thought that Chinese dragons like Yinglong and Shenlong were kinds of gods who had power over where the water in rivers and canals went and when the water in clouds would fall as rain. Because this was very important for farming, dragon dances could happen all through the year when rain was needed. Different parts of today's dragon dances began at different times, with some at least as old as the Song (about 1150) and others very new, like using special paint that glows under black light.