Invisible to our eyes, but found everywhere. Here is your kitchen cutting board viewed with an electron microscope. Penicillin destroys bacterial cell walls without affecting human tissues, unlike many other antibiotics that have side effects. Some bacteria motile, many are not. Some move by flagella , others by gliding .
Some bacteria have specialized dormancy structure, the endospore .
Endospores can survive boiling for up to several hours, can be revived after decades of dormancy. One recent report suggests reviving dormant endospores from insect gut trapped in million year old amber. Spores from woodland pond. Anaerobic environments . Normal flora or microbiota help us break down food, reduce risk of infection.