Why bottles fail quietly in a big cage
A water bottle gives no visible signal when it stops working. The ball bearing in the spout can stick after a knock or a mineral build-up, a seal can start dripping the bottle empty overnight, and degus — committed gnawers — can wedge bedding into a spout or chew at its mounting until it angles wrongly. In a small cage you would notice an untouched bottle; in a large multi-level setup with several bottles and a group of degus, one dead bottle can hide behind the others for days. The checks below take under a minute each and are built around the three failures that actually happen: no flow, too much flow, and a bottle nobody can reach.
The flow test, morning and evening
At each check, press and roll the ball bearing at the tip of every spout with a clean fingertip. Water should wet your finger immediately and an air bubble should rise inside the bottle as it does — that bubble is your proof that water moved. A dry ball that will not roll means the spout is blocked or jammed; swap in a spare bottle straight away and sort the blocked one at the sink, because a degu group should never be left with one fewer working bottle than the check started with. Do the rounds in the morning before the group's most active period and again in the evening; degus drink in bouts around their activity, and twelve hours is about the longest a blockage should ever go unnoticed.
Levels, leaks and reach
Mark each bottle's water level with a small line at the evening check so the next morning tells you at a glance roughly how much the group drank — a bottle that has not dropped at all overnight pairs with the flow test as an early warning. Run a hand over the bedding beneath every spout: a damp patch under a bottle that has emptied far faster than the others means a leak, and degus sitting in a cage with wet bedding and one less water source are doubly worse off. Position matters as much as mechanics in a tall cage: fit at least one bottle on every level, low enough for the smallest degu to reach comfortably, and after any cage rearrangement, watch that each degu can actually get to a bottle without crossing a cage-mate's favourite sleeping shelf.
Drinking changes are information
Degus are notably prone to blood-sugar problems, and a real change in how much a degu drinks is one of the few early clues an owner can catch at home. You cannot track individuals at a shared bottle, but group intake that suddenly climbs across all bottles — levels dropping faster day after day with no leak found — or a degu seen returning to the spout again and again deserves attention. Note it, weigh the degus that week, and if the pattern holds over several days, raise it with a vet rather than waiting for other signs. A clean, dated record of 'bottles draining twice as fast since the weekend' is far more useful at that appointment than a general feeling that they seem thirsty.
Rotas make the checks survive busy days
Bottle checks fail in the same way most small pet routines fail: each person in the household assumes someone else did them. Making the morning and evening rounds an explicit duty in KinsLe's Care Teams — with the spare-bottle rule and the level marks written into it — means the degu group gets working water verified twice a day regardless of whose evening it is, and a problem found on one round is visible to whoever does the next.