Why Some People Put Water Bottles Outside Their Homes

If you’ve walked through towns in Italy—or increasingly in other countries—you might have noticed something odd: plastic water bottles placed outside doorways, garages, or in building corners. At first, it seems like a quirky habit. But for many, this is a deliberate tactic aimed at a very specific goal: keeping animals from peeing on walls.

The Idea Behind the Bottles

Homeowners who use this method believe they are deterring dogs or cats from marking their property. The theory is that water-filled bottles create reflections or glints that confuse or startle animals, making them think another animal is nearby. Some suggest the bottles act as a visual warning to pet owners, signaling that the area is “claimed” or monitored.

In short: the bottles are intended to discourage animals from choosing certain spots to urinate.

Myth vs. Reality

Despite how common this practice has become, there’s no scientific evidence that it works. Animal behaviorists agree that dogs and cats are not reliably deterred by water bottles. The method seems to be more of a folklore solution—a low-cost, harmless attempt at prevention. While it may give homeowners peace of mind, it rarely provides actual protection against pets marking walls.

More Effective Alternatives

If your goal is truly to keep pets away from your walls, consider these proven strategies:

• Clean up immediately: Rinse or spray the area with water or a mild, pet-safe cleaner to remove scents that encourage repeat marking.
• Use repellents: Pet-safe sprays or gels can consistently discourage marking.
• Install barriers: Low fences, thorny plants, or shrubs make walls harder to access.
• Try motion-activated deterrents: Devices that emit water sprays, sounds, or lights can startle animals before they mark.
• Supervise and train pets: When possible, guide pets to appropriate areas and discourage them from approaching off-limit spaces.

Though these methods require more effort than placing a bottle, they deliver measurable and consistent results.

Why the Bottle Trick Persists

If it doesn’t really work, why do people keep doing it? Several reasons explain its popularity:

• Simplicity: Fill a bottle with water and leave it—no skill required.
• Placebo effect: Homeowners feel like they’re doing something proactive, even if results are coincidental.
• Tradition: The idea spreads through neighbors and communities—“it must work because everyone does it.”
• Harmlessness: It seems safe and inexpensive, so people think, “Why not try it?”

The Bottom Line

Water bottles outside homes are a quirky, low-cost attempt to prevent animal marking—but there’s no proof they actually work. For real results, rely on cleaning, repellents, barriers, or deterrent devices. The bottle method persists largely because it’s simple, harmless, and visually “logical,” but if you’re serious about keeping pets away, proactive strategies will serve you far better.