The patent-leather beetle or “Jerusalem beetle” (Odontotaenius disjunctus) is a beetle in the family Passalidae which can grow to just over an inch-and-a-half long. They are shiny black and have many long grooves on their elytra. They have a small horn between their eyes, and clubbed antennae. When disturbed, adults produce a squeaking sound by rubbing their wings on the abdomen. This is called stridulation, and is often easy to hear. This is apparently used for…