It's well known that golf tees can be used to fix stripped-out screw holes, such as door hinges.

Those are the military's stock reserves of very large plugs for right- (blue)
and left- (pink) threaded holes in ships, docks, pipes, caves, etc.
.

OK, what is it?

smut

Nope.

If it's not red caviar on celery, then I want to know how many times the image is magnified.

Creepy. Looks like a teeming mass of chiggers.

Fish eggs on water grass.

Not fish eggs, chiggers or caviar.
Magnified a lot.

pollen?

Nope.

Blood?

Yes, blood on a gauze pad.

Believe it or not, I saved this same image for use in this thread.

I have no idea. It's been around the house as long as I can remember.

Something left from your Dad's store?