If a bacterium is trying to infect you, it won't secrete alone, because your immune system will block it. Bacteria will hide until they can all act together and make an impact.

What's great about bacteria is you have a surprise every day waiting for you because they're so fast, they grow overnight.

You live in intimate association with bacteria, and you couldn't survive without them.

Bacteria mineralized the rocks; they deposited the iron. They made the geology we see.

All these bacteria that coat our skin and live in our intestines, they fend off bad bacteria. They protect us. And you can't even digest your food without the bacteria that are in your gut. They have enzymes and proteins that allow you to metabolize foods you eat.

You can find bacteria everywhere. They're invisible to us. I've never seen a bacterium, except under a microscope. They're so small, we don't see them, but they are everywhere.