The question in the title might, at first instance, look completely normal. Domestic cats hunt in order to feed themselves, surely? But domestic cats don’t need to hunt to eat. In nearly all homes, they are provided with commercial cat food. They have all the niceties of being in a good home that the domestic cat requires. Why should they hunt prey under these circumstances?
Desire to hunt not motivated by hunger
The obvious answer is that the motivation to hunt and the sensation of hunger are separated in the domestic cat. People eat when they are hungry or they should do. Domestic cats hunt because they are finely tuned to respond to sensory stimuli which signals the presence of prey. The signals are both auditory and visual. A domestic cat will be motivated to hunt if and when she receives the correct sensory stimulation.
Stimuli
This might be the sound of rustling in undergrowth which would normally signal the presence of a small mammal like a rodent (a mouse or vole). And visually you will find that a cat is stimulated to hunt all the time even inside the home. They respond to fast movements. For example, this morning my cat had just come in from the outside and was somewhat wound up. He wasn’t looking while I’m placed my hand behind his forehead to stroke him. It caught him by surprise and he turned to bite my hand. It was a hunting response, there is no doubt about that. I was not harmed but the quick movement of my hand in that instant, when he was still mentally in the wild, provoked his hunting response.
Hunting because of hunger
If a cat relied upon being hungry before they hunted it would place them in a vulnerable position because they would be weaker than normal. This is why they are motivated to hunt because of specific sensory cues.
Friendly greeting to avoid bite
Jackson Galaxy has its own specialist way of meeting a cat that he does not know to avoid creating a hunting cue. He calls it the Michelangelo technique. It is an outstretched hand with bent fingers in a passive position with one finger stretch forward more than the others to touch the recipient’s nose. It is a version of the cat-to-cat nose touch greeting which is friendly. It avoids the predatory instincts of a domestic cat and relays to the cat that you are friendly.
Public image
The problem with domestic cats hunting when they are well fed is that it gives them a public image which is less than good for their welfare. People sometimes regard domestic cats as self-indulgent predators killing for the pleasure of it. When it comes to birds people who are not cat owners become unhappy. This is partly because people also practice speciesism. They rank birds over cats if they are not cat owners. When a cat kills a bird (or endangered native ground dwelling species) as a predatory action and they’re not hungry they are blamed by some government bodies who want to exterminate outside cats for this very reason.
Conclusion
The key issue about this is that, as mentioned, domestic cat don’t hunt because they’re hungry. They hunt because it is in their DNA that they have to respond to signals both visual and auditory which tells them that prey exists at a certain point. This in turn provokes a domestic cat’s predatory instincts to attack and kill. If they are hungry it may motivate them to hunt in a more committed way.