Key Takeaways
- Grass eating is common and usually harmless, though frequent vomiting afterward deserves a vet conversation.
- Chewing furniture is almost always a sign of insufficient mental or physical stimulation, not spite.
- Dogs detect sounds and scents far beyond human range, so barking at 'nothing' usually means something is there.
- Repetitive or escalating versions of any behaviour warrant a professional evaluation.
- Addressing the underlying cause, such as boredom or anxiety, works better than simply trying to stop the behaviour.
Normal dog behaviour vs. a problem
Dogs communicate through action, not words. Behaviours like eating grass, chewing objects, or barking at seemingly nothing are often normal expressions of instinct, boredom, or sensory responses. The challenge for owners is knowing which behaviours fall within a healthy range and which ones signal stress, illness, or a need for intervention.
Veterinary behaviourists distinguish between behaviours that are species-typical (normal for dogs as a species) and those that are pathological, meaning driven by anxiety, compulsion, or underlying medical conditions.
Why dogs eat grass
Grass eating is one of the most frequently reported 'strange' dog behaviours, and it is also one of the least understood. The honest answer is that researchers have not pinned down a single cause. Several explanations have evidence behind them, and more than one can be true at the same time.
One observation from animal behaviour research is that many grass-eating dogs do not vomit afterward, which undermines the popular idea that dogs eat grass specifically to make themselves sick. Some dogs may eat grass because they find it palatable. Others may do it out of habit, boredom, or as a response to mild gastrointestinal discomfort. Wild canid ancestors consumed plant matter regularly as part of their diet, so the behaviour has a plausible evolutionary basis.
What should prompt a vet conversation is not the grass eating itself but what surrounds it: frequent vomiting, signs of abdominal discomfort, or a sudden increase in how much grass your dog is consuming. Grass treated with chemicals is also a real hazard worth knowing about.
Check the grass before your dog grazes
Before letting your dog eat grass freely, find out whether the area has been treated with pesticides, herbicides, or fertilisers. Many lawn chemicals are toxic to dogs. Untreated grass in your own yard or a known-safe park is a much lower risk than grass in public areas that may be regularly sprayed.
Why dogs chew furniture and belongings
Chewing is how puppies explore the world and how dogs of all ages relieve tension and keep their jaws active. The problem is not chewing itself but where it gets directed.
When a dog chews furniture, shoes, or baseboards, the most common reasons are insufficient exercise, lack of mental stimulation, and anxiety. A dog left alone for long hours with nothing to do will find something to do. Furniture happens to be accessible, has interesting textures, and carries the scent of the people the dog is attached to.
Destructive chewing that happens only during owner absences points more specifically to separation anxiety, a genuine stress response rather than defiance. Dogs do not chew out of revenge or spite; those are human concepts dogs do not share. Attributing human motivations to chewing behaviour tends to lead owners toward punishment, which does not address the actual cause and can make anxiety worse.
The practical approach is to increase daily exercise, introduce puzzle feeders or food-stuffed chew toys, manage the environment so the dog cannot access problem items, and seek veterinary or behaviourist guidance if anxiety is the driver. Persistent physical symptoms like scratching follow a similar principle: address the root cause, not just the symptom.
Why dogs bark at seemingly nothing
Dogs hear frequencies roughly four times higher than humans can detect, and their sense of smell is estimated to be tens of thousands of times more sensitive than ours. When your dog barks at a blank wall or an empty yard, the most probable explanation is that your dog has detected something real that you simply cannot perceive: a person outside, an animal under the floorboards, a distant siren, or a scent carried on the wind.
Context helps sort out what kind of barking is happening. Alert barking at the front door is different from anxious barking triggered by nearly any sound. Demand barking, where a dog barks to get attention or food, has a distinct rhythm and usually stops when the reward is withheld consistently.
When to be concerned: barking that is new, that seems confused or disoriented, or that is accompanied by changes in sleep, appetite, or movement may indicate a medical issue. In older dogs, repetitive vocalising directed at walls or corners can be a sign of canine cognitive dysfunction, the dog equivalent of dementia. A veterinarian can assess whether the behaviour has a physical cause.
This article is for general informational purposes only and is not a substitute for professional veterinary advice. Always consult a licensed veterinarian if you have concerns about your dog's health or behaviour.