Cold is rarely the problem
Ducks are among the hardiest of domestic birds in winter. Their waterproof feathering and the layer of fat beneath it insulate them against temperatures that send hens huddling, and a healthy adult duck in good condition will bathe happily in water skimmed with ice. What actually makes winter dangerous for ducks is the combination of wet bedding, frozen drinking water and hunger: foraging disappears under frost and snow, the ground gives up its insects and greens, and the duck's energy bill for staying warm climbs steeply. Winter duck care is therefore a short list of provisions rather than elaborate protection, and a flock that gets them will usually sail through to spring.
Water they can dunk in, every day
A duck must be able to dip its whole head — it washes its eyes and clears its nostrils in the water, and ducks denied dunking water develop sticky, infected eyes and sinus trouble. Swimming water is optional in the coldest weather, but head-deep water is not: a sturdy bucket or trug, refreshed daily, does the job. Frozen mornings need a plan — carry out warm water, swap frozen buckets for fresh ones, or float a ball on the surface to slow the ice — and site the bucket on slabs or gravel so the inevitable splashing drains away instead of building an ice rink of mud around the house.
Housing: dry, draught-free, ventilated
Night housing should give ducks deep, dry straw they can nest down into, out of the wind but not sealed airtight: damp, stuffy air encourages the respiratory problems that spread through a shut house, so ventilation high up, away from where the ducks sleep, is the balance to strike. Bedding wants regular topping up and a full clean-out whenever it starts to feel damp underfoot, because ducks are wet birds and their bedding degrades fast. Check house security with extra care in winter — hungry foxes work harder, and the long nights give them more cover — and bring the flock in before dark without fail.
Feeding up and watching feet
Offer more of their usual layers or waterfowl pellets through the cold months, with some whole grains scattered in the straw to encourage activity, and greens whenever you can supply them, since the garden stops providing. A duck that is eating and active is coping; the birds to watch are any that go quiet, hang back from the flock, or start limping. Feet take winter punishment: check for limping, swelling or a warm, tender pad, because foot infections establish quickly on frozen, rough ground, and a limping duck with a swollen foot needs the vet rather than another week of watching.
Eggs and daylight
Most ducks ease off laying as the days shorten, and that pause is normal rather than a problem: their bodies are redirecting energy towards warmth and feather maintenance. Do not chase winter eggs with rich feeding; keep the ration steady and let laying resume with the light. Collect any eggs promptly in freezing weather, before frost cracks the shells. Weather questions change by the day in hard frost, and for any that puzzle you, put a follow-up question to KinsLe's Kinny; he answers using the KinsLe Answers library.