Mushi

The bugs are machines that operate on white Kemurikusa. They lack the sense of purpose and always ask for tasks. When stacked together they can transform into larger Mushi.

Akamusi
The Red Bugs (あかむし, Akamusi) are the antagonists in the series, they are neutral Mushi possessed by the red Kemurikusa. They seem to be drawn to the girls with aggressive intentions. They look like mechanical insects with red lights and varying sizes. Rin has the ability to turn the smaller bugs neutral using her Kemurikusa, they will then turn their color to neutral white.

Nushi
Nushi is a categorization of Mushi that the Sisters give to the large Mushi.

Blue Mushi
At one point we see neutral turn into blue colored Mushi, just like Akamusi are red. This was not explained, but it is probable to guess that the huge dormant Midori was their master.

Friendly Mushi

 * Shiro
 * Nushichi