Pet Bottles are real!
They exist for a purpose, although they have been scientifically proven to be inaffective. While the origin of this curious phenonem is disputed, clearly it crosses cultural boundaries. Pet Bottles can be found in Austraila, Japan and the United States.
Purpose: To repel animals, mainly dogs and cats away from the area.
Sightings in Japan: Usually found around planters, flower boxes and gravel areas surrounding Shrines or other sacred locations.