Monster In The Sky, By Brian37 (AKA Brian James Rational Poet on FB/META and @brianrrs37 on Twitter/X)

Brother and sister, hide under the bed
They peer from under look up in dread
What is that spinning thing over my head

Five arms of mocha, four eyes of alabaster
Whirling dervish, fixed and inverted
Pull one chain , light at night, day converted

Camel spin 5, pirouette, fouette, centrifuge
That monster on the ceiling is so huge
What if it is an owl that swoops down to
Make a meal of us, are we going to be it’s food?

Daddy doesn’t seem to care, the stiff starfish
Blows a lot of cool air, but for now be aware
Of that thing on the ceiling, gives us a scare
It hangs high above our favorite chair

Should we try to sit under it, we do not dare
Why is that monster, spinning so fast
I hope the fears of my two cats
My newly installed fan will not last
(end)

I just got a new fan installed, and my cats were petrified of it, hid under the bed for hours. I did manage to coax them out for dinner. But any time I turn the fan on they run under the bed.

Evolutionary wise, they probably see the ceiling fan as some sort of large predatory bird, like a feral cat might see in the wild.