I was walking the overpath and heard hammering noise, and there it was, an ice-pecking raven. You can hear the sound as the guy pecks in the attached video (PXL_20261008_233238334TS~2.mp4, use headphone). I was shooting from the middle of the overpath slope, so it was kind of far but the noise was very much audible.

Thick layer of ice formed around the LN2 pipe, see picture (PXL_20261008_233616363MP.jpg).