Why On Earth Do Some People Line Up Plastic Milk Bottles In Their Yards?
As a kid I remember people putting rootbeer-colored or green gallon Clorox or Purex bottles around their yard, filled with water. Those big round glass jugs are no longer used for Purex, so nowadays people do it with gallon white plastic milk bottles. Ever wonder what on earth underlies this unsightly tradition?
There is a widespread belief that these bottles can scare off moles. Others have believed bottles of water frighten away dogs & cats, though when asked why that would be, such folks find it hard to justify the belief. Reason would suggest the repelling capacity of water bottles is nonsense, unless the bottles are so close together a dog can't find room to squat. The practice's actual origin is completely different from the explanations superimposed by observers. The "it frightens away dogs & cats" explanation seems to have been as close as some people could come to understanding the superstitious practice, & sometimes imitated the practice for that very imagined value. But originally the water-bottle tactic intended to take advantage of an almost universal myth found everywhere from China to Europe & throughout Hispanic America & among Oceanic peoples — that ghosts, witches' curses, & vampires cannot cross over water. Pacific Islanders & Latin Americans have been especially prone to lining bottles of water around their houses to keep out bad luck, ghosts, disease, & all unpleasant things.
Tongans & Samoans surround their houses with bottles of water for a short duration after the death of a loved one, so that the loved one will not mistakenly return home as a ghost instead of continuing on to their proper reward. Many hispanics reproduce this protective device, but to keep away evil spirits rather than to assist departed loved ones. It seems mostly to be white people who imitate the practice with the silly expectation that dogs won't poop anywhere near, nor moles burrow beneath, bottles of water. Appalachian whites, however, do it to scare off spirits rather than dogs. It would work on a dog only if it was a ghost-dog.
The newer misunderstanding of this old folk-practice is infecting even communities that once did it to scare away spirits. Some Maori will tell you they do it "so dogs won't pee in the garden" like any suburban idiot in America. Well, insofar as it is believed to repel bad things, the explanation hasn't changed that much. To this new meaning was added the faux "scientific" explanation that dogs won't poop near water, which they want to keep clean so they can drink it. More likely so the turd won't be washed away before they come back to eat it!
A variation of the myth is how a bag of water in the yard will repel flies. This may have been derived from a very old practice of having an open bucket of sweetened or otherwise baited water in a barn, where flies drown when attracted to the sugar. Since flies carry diseases, it may also relate to a practice common in India, of placing a jug of water on the roof of houses to appease the Pox-mother Shittala, who if provided with something to drink will not enter the house to give the residents an illness.
When this topic came up in a newsgroup, there were plenty of gardeners who insisted it doesn't work on dogs, but it really does keep cats from pooing in the yard (never mind that cats don't as a rule shit on the grass, but bury their turds in soil — we're not dealing with reason here but superstition). Plenty of people are convinced that when they tried it, it had a genuine repellant effect on something whether moles or dogs or cats or squirrels or flies. Yes, & when I stubbed my toe in the garden, a bunch of people died in China.
What seems actually to be true is that in this day & age — when very few Americans are worried ghosts or vampires or witchcraft curses getting in the house — many do still worry about the "evil thing" that is dog urine, mole holes, or cat poo. Therefore an abjectly nonsensical superstitious practice endures.