What architectural feature in ancient structures is named for the *uguisu* because of a deliberate squeaking mechanism?

Answer

*Uguisubari* (nightingale floor)

The *uguisubari*, or nightingale floor, was engineered to squeak under pressure, producing a sound similar to the bird's soft chirping to alert occupants of intruders.

What architectural feature in ancient structures is named for the *uguisu* because of a deliberate squeaking mechanism?
namebirdanimaltranslationUguisu