The statement "We do not want to sell this cat. It is giving us good service" indicates that the cat is providing a valuable function or benefit to its owners. This could be related to:

• Pest Control: Cats are natural predators and can effectively control rodents and other pests around a property.
• Companionship: The cat may provide emotional support and companionship to its owners.
• Therapeutic Benefits: Studies have shown that owning a cat can reduce stress and improve overall well-being. Source: CDC - Healthy Pets, Healthy People

Therefore, the owners' decision not to sell the cat is based on the perceived value and benefits it brings to their lives.