Fig 2. Schematic overview of the multiple time scales present in Drosophila melanogaster grooming ethograms.

Grooming ethograms possess at least three distinct time scales. The grooming progression (top), which takes many minutes to observe in its entirety, occurs at the longest time scale we consider here. We refer to this phenomenon as a progression because we observe that, on average, flies begin grooming with anterior-oriented actions and end with posterior-oriented actions and more walking. At an intermediate time scale, ethograms consist of grooming motifs (middle). Motifs are composed of consecutive grooming bouts which use the same pair of legs (either anterior or posterior). At the shortest time scale, we observe individual grooming bouts (bottom), which consist of sustained grooming movements that range from several hundreds of milliseconds to a few seconds in duration.