Dead skin ...

I'm not ready to sign off on that. Seems awfully like fiber to me.

And lots of dust. Ugh.

lots of really fun things to think about.

and lint and dust keep that secret.
My dog stirs the house up and brings debris in. Some dust can travel very far. Dust from a local stone grinding company travels miles. Cars are covered at times. My towels never fail to give me a good lump of lint?

"As sure as the sun rises, houses collect dust. It gathers on our knickknacks and dirties the carpets. More than just dirt, house dust is a mix of sloughed-off skin cells, hair, clothing fibers, bacteria, dust mites, bits of dead bugs, soil particles, pollen, and microscopic specks of plastic. It’s our detritus and, it turns out, has a lot to reveal about our lifestyle......."
https://cen.acs.org/articles/95/i7/Tracing-chemistry-household-dust.html

carpets are shoe cleaners if not removed at the door.

The outside air is full of stuff. Unless you live in an airtight box and scrub all the air coming in, you will have dust. They (smart people) say that too much cleanliness is unhealthy for children.

lovvvvves to roll on the dirt.