A young border collie lies rigid on the kitchen floor, eyes fixed on the gap beneath the sofa. A ball rolled there an hour ago and has not been retrieved. Food is offered, a lead is rattled, a familiar voice calls — but the dog does not move. Researchers analysing more than 1,600 canines recently documented this exact behaviour: some dogs, they found, become so intensely motivated by a toy that they will prioritise its retrieval over eating, and remain unable to settle long after the object has vanished. The study, published in The Royal Society Open Science, describes a pattern of craving, frustration and loss of self-control that parallels behavioural addiction in humans. Shepherd breeds scored highest, followed by terriers and retrievers, suggesting that the very persistence prized in working lines can, in a domestic setting, tip into something less adaptive.

Viewed from the United Kingdom, where the study was conducted, the findings add a new layer to a long-running conversation about the inner lives of companion animals. The neurochemistry is now well mapped: physical closeness between dog and owner triggers a release of dopamine and oxytocin, the same hormonal cascade that underpins human bonding. Specialists in Latin America note that this is why dogs seek to sleep pressed against their humans — a modern expression of an ancestral pack instinct for shared warmth and mutual protection. The bed becomes a den, the owner a pack leader, and the nightly ritual a neurochemical contract that lowers stress in both parties. Yet the same experts caution that hygiene and physical safety must not be overlooked; older dogs, in particular, risk injury jumping on and off high mattresses.

Humans, it turns out, construct their own sleep architectures with equal care. Psychologists at the University of Oxford have observed that the habit of sleeping surrounded by multiple pillows is rarely just about comfort. The repeated act of arranging cushions each night functions as a safety signal for the brain, a ritual that generates predictability and eases the transition into sleep. In moments of anxiety, the behaviour intensifies: pillows become a form of self-regulation, a soft barrier against the day’s residue. Russian neurologists, however, warn that not all nocturnal postures are benign. Sleeping with a hand tucked under the head, they note, can keep neck muscles in a state of tension for hours, leading to morning headaches, numbness in the fingers and, in some cases, the sudden aggravation of spinal protrusions. The wrong pillow height — too lofty, too flat — can compress vessels and nerves, turning a gesture of comfort into a source of chronic pain.

In Brazil, a quiet rethinking of what dogs truly need is unfolding beyond the laboratory. Behavioural specialists there argue that a large house and a grassy yard, however generous, do not automatically confer quality of life. A dog that never leaves its property, that never walks, sniffs or explores at its own pace, accumulates a tension that no amount of indoor affection can dissolve. The structured walk — slow, exploratory, guided — is emerging as a form of emotional hygiene, a daily practice that returns the animal to a state of calm alertness rather than mere physical exhaustion. One owner in São Paulo, whose three dogs have access to over two thousand square metres, describes the transformation after years of such walks: the animals, she says, are now “more tranquil, more balanced, much more present.”

What connects the toy-fixated collie, the pillow-builder and the dog that finally sleeps soundly after a long, sniffing walk is a shared search for regulation. The rituals of the night — the arrangement of cushions, the warmth of a canine body, the quiet retrieval of a ball — are not trivial. They are the small, repeated acts through which two species negotiate safety, arousal and rest. In a world that often prizes space and stuff over rhythm and presence, the evidence from the bedroom and the living room suggests something quieter: that the architecture of a good night is built not of square metres, but of predictable gestures, mutual warmth and, sometimes, a single, irreplaceable toy.