Why They Do It: Understanding Their True Motives

If you stroll through some quiet neighborhoods, you may spot clear plastic water bottles neatly lined along fences, walls, or garden edges. At first glance, they look like discarded drinks, but they are actually part of a folk practice called “cat repellent.”

While cats are beloved pets, stray cats can sometimes cause problems, such as digging in gardens, marking territory, or posing minor health risks. Some homeowners use water-filled bottles outside to deter cats gently and without harm.

The method is based on light and reflection. Sunlight or artificial light hitting the bottles creates flashes or reflections that may startle or confuse cats. Some believe the reflections distort depth perception, while others think cats see their own mirrored image and hesitate.

Another explanation is that the reflections create visual “noise” in a cat’s peripheral vision. Cats rely heavily on subtle motion cues, so these unusual reflections may appear threatening or simply unfamiliar.

The practice may have originated in the UK or the U.S. in the 1980s to keep dogs away from yards. Later, it was adapted to focus on cats, with attention to symmetry and aesthetics, making it both functional and visually organized.

Experts say the technique isn’t reliably effective. Many cats eventually ignore the bottles, especially in shaded areas, and some curious cats may approach or knock them over. Nevertheless, it persists because it’s harmless, inexpensive, and easy to implement.

Today, water bottles serve as both a practical tool and a cultural curiosity, symbolizing creativity, tradition, and gentle problem-solving. They reflect a thoughtful approach to coexisting with nature in everyday life.