Toothbrush bristles, looking like otherworldly bottom-of-the-sea creatures that feast on plaque.
The white cruddy stuff on the tips of the bristles is dried toothpaste. That's what I'm telling myself. Come on, I can't post a clean, fresh, new toothbrush... a used one is so much more fun.
I haven't looked at other toothbrushes, but I would imagine that they too have rounded bristle ends, for comfort. These look rubbery and thick in the photo, but I assure you that these are the standard, regular old thin plasticky bristles just like on your toothbrush.
Send me your suggestions for something tiny that you'd like to see big.