Burrows do the heating in winter
A gerbil colony meets winter underground. Tunnels and a packed nest chamber hold body heat from several animals, buffer the swings of a heated house, and give every gerbil a retreat from cold air. Your winter job is therefore to protect the burrow system and the room around it, not to add heaters to the tank. Keep the gerbilarium where room temperature holds roughly in the high sixties to mid-seventies Fahrenheit without cold drafts washing over the mesh top.
Position matters more than equipment. A tank under a window cools at the glass all night, a tank by an exterior door takes a blast of cold air at every opening, and a tank on a cold floor loses heat through its base. An interior wall in a lived-in room, raised off stone or tile if needed, gives the burrows a stable starting temperature. A simple thermometer beside the tank, read on cold mornings, confirms the spot you chose is performing as expected.
Bedding depth and nesting material
Winter is the season to be generous with substrate. Fill the tank deep enough for genuine tunnels with a nest chamber, using a suitable dust-extracted bedding that holds tunnel shape without collapsing. Add plain paper-based nesting material the gerbils can shred and carry; a finished nest should look bulky, dry, and fully enclosed, with gerbils disappearing into it rather than sleeping exposed on the surface.
Top up rather than replace through the coldest stretch. Full clean-outs in midwinter destroy the tunnel network and the scent map the group relies on, and rebuilding costs energy exactly when gerbils should be conserving it. Spot-clean damp or soiled corners, refresh the sand bath area, and when a fuller clean cannot wait, return a generous portion of clean old bedding and the intact nest material so the colony rebuilds around familiar insulation.
Group warmth, food, and water checks
Keep bonded gerbils together through winter; a single gerbil loses the shared warmth and social grooming that are part of its winter welfare, as well as the comfort of huddling. Watch that all members reach food and the nest, since a larger group in deeper bedding can hide a smaller gerbil being edged out. Scatter feeding through the bedding spreads access and encourages the digging activity that keeps gerbils fit and warm.
Check water daily and test the bottle valve with a fingertip. Cold rooms and cold bottles make valves stick, and a colony can drain a working bottle faster on dry heated air than owners expect. Keep the usual seed and pellet mix consistent, add no sugary winter extras, and monitor body condition by observation and brief handling in the evening, since weight changes in one gerbil are easy to miss inside a busy group tank.
Signs the tank is too cold or a gerbil is unwell
Comfortable gerbils in winter stay busy in their active periods: digging, gnawing, running, and emerging for food with bright eyes and full cheeks. A group that stays buried all day and evening, gerbils that feel cold to the touch, shivering, or one animal sitting hunched and puffed away from the others all call for action. First fix position and bedding and confirm the room has not dropped, then seek veterinary advice for any gerbil that stays hunched, eats poorly, breathes noisily, or loses weight.
Never warm gerbils with a heat lamp aimed into the tank or a hot pad under glass, which can overheat one area and leave gerbils choosing between cold and cooking. Gradual room-level correction and better insulation are the safe levers.
One tank plan for the whole household
Gerbil care is often shared between adults and children, and winter details are the first to drift: bedding filled shallow, the tank nudged toward a window for light, the bottle checked by nobody because everybody assumed someone else had. Settle the winter depth, position, and check routine once and keep them visible. Family Sharing on KinsLe means a relative you pick can be given access to their profile, so spot-cleaning around established burrows can begin with that profile open and the tunnels undisturbed.