This probably isn't the answer you are looking for, but they bathed more than the common people of their era and slightly less than people of today.
Hope this helps even a little.
The fact that there is an entry for fireflies in Kitamaru Kigin's manual for poetry suggest numerous things <span>about the roles of animals in Japanese poetry. It represents nature as well as a season for different things. They are actually representing the cultural life of the Japanese and it does not carry much biological significance.</span>
