Field note. The organism enters a small vertical chamber, seals itself inside, and voluntarily triggers a controlled indoor rainfall onto its own dorsal surface.
The temperature-regulated liquid, two parts hydrogen to one of oxygen, is delivered under pressure from a perforated disc mounted overhead. The human adjusts the thermal output with obsessive care, waving a limb through the stream, retracting it, adjusting again, seeking a narrow band of heat it never articulates but always recognizes.
Too cold: the organism recoils and hisses. Too warm: the same. The acceptable range appears to be a fraction of a degree wide and locatable only by the animal itself.
Once satisfied, it does something I cannot classify. It stops functioning. The limbs slow. The head tips forward under the falling liquid. The eyes close, though no rest is occurring and no threat has passed. It simply stands in the heat and the noise and the rising vapor, absorbing water it does not drink, achieving nothing measurable, for a duration far exceeding what hygiene could require.
I have logged the applied substances: a viscous foam for the fur, a second foam for the surface it stands on, a slick paste it presses to its rows of grinding structures. All are rinsed away immediately. The organism creates dirt in order to remove it. The process is circular and produces no net product.
Correction to earlier hypothesis: I had catalogued this chamber under maintenance behavior. The data no longer support this. Maintenance concludes when the surface is clean. This does not conclude. It continues until an external signal, another organism, a depleted heat reserve, an obligation, forces the animal out, at which point it emerges visibly reluctant.
Revised classification: the human has engineered a small warm rain it can enter on command, in order to be somewhere no one can reach it.