A childhood belief about excursions

When I was a kid, about 5 years old, my dad and older brother thought it was funny to tell me that oil pumpers (the kind you see in Texas and Oklahoma) were actually monsters that pumped oil from the ground. Because they make this funny "heart beat" noise when they pump, I was deathly afraid of them, and would hide whenever we drove by.

My mom got mad at my dad about it, and so my dad and my brother thought they could cure me by driving right up next to one and parking there for a bit. They were rolling laughing at how much I was screaming and crying, which made me so mad that I forgot about the pumper! To this day, it still freaks me out to hear that sound (or the sound of a heart-beat).