Ophanim:
The ophanim (Hebrew: אוֹפַנִּים ʼōp̄annīm, ‘wheels‘; singular: אוֹפָן ʼōp̄ān), alternatively spelled auphanim or ofanim, and also called galgalim (Hebrew: גַּלְגַּלִּים galgallīm, ‘spheres, wheels, whirlwinds‘; singular: גַּלְגַּל galgal), refer to the wheels seen in Ezekiel‘s vision of the chariot (Hebrew merkabah) in Ezekiel 1:15–21. One of the Dead Sea scrolls (4Q405) construes them as angels; late sections of the Book of Enoch (61:10, 71:7) portray them as a class of celestial beings who (along with the Cherubim and Seraphim) never sleep, but guard the throne of God. In Christian angelology, they are one of the choirs (classes) of angels, and are also called Thrones. [Wikipedia]
Never sleep? I’d expect them to be insane. Noted in this video.