Snake
My neighbor poured a snake repellant that smells like sulphur along the property line. Two weeks later, she added mothballs. It is a sickening combination that can be detected throughout my garden.
She has never seen a snake but someone on another street reported on a black one. She did not mention the size, but I have never seen a large snake, or even a medium sized one. Snakes are good at hiding.
I didn't ask my neighbor how she would know if the sulphur and mothballs were blocking the snakes out or trapping them inside her yard.
Not that I mind snakes in my own yard, at least theoretically. They control pests in the garden.
I didn't tell my neighbor about the baby gray snake hiding under a log near the hellebores. Or the soft pink baby along the pathway. The pink was the underside and this snake was already dead, intended as a meal for a predator.
My neighbor would not understand that life is hard, even for a snake.