Confused by what this might be? So were scientists for several hundred years. Apparently, the occupant of this contorted alder root also likes hanging out on your floor. Find out more below. Creative Commons Lebrac. Click image for source and license.

It's no longer any secret that our skin and various mucusy surfaces are microbial zoos. So are our homes. What is less well known is what the individual species in those zoos look like and are doing. An early attempt to combat this ignorance has been cooked up by project frequent Sci Am guest blogger and biologist Rob Dunn: the Book of Invisible Life. As Dunn explains,

In this Book of Invisible Life, we have asked leading scientists and science writers to tell the story of some of their favorite kinds of microscopic life. The book is a work in progress, but when completed will include more than twenty stories of the life on, in, and around you, stories that I guarantee will make you reconsider who and how you are. These are stories about your partners in living, partners that are intimately attached to your daily life, even though you probably don’t know their names.

These are the same folks who have been asking people to swab their belly buttons and door frames (which I wrote about here last year) to see what's living there. As they explained it to me, the book project arose when the swabs' contents generated long lists of names, but Your Wild Life team had no easy way to tell curious swab donors about the microbes behind the names. So they figured -- hey, isn't this what our science writer buddies are for? Touché.

I have contributed two short (~1,000 word) stories: "Mycoplasma" and "Frankia". "Mycoplasma" tells the tale of the world's tiniest free-living microbes, who, through long acquaintance with vertebrates, have reached their present diminutive (some might even argue cute) state. Several species may be living inside you right now. Some of them have some intriguingly unique, non-flagellum-based ways of getting around, and as I wrote about here last fall, the gutted exteriors of M. mobile can even be resurrected as gliding zombies. Here are some very much alive Mycoplasma mobile driving around in their, well, mycoplasmamobiles.

You can read the Inivisible Life Mycoplasma story here.

"Frankia" tells the story of a bacterium that looks and acts like a fungus, hangs out inside trees, and is also apparently quite fond of (or at least familiar with) your floor -- particularly if you own a dog. I wasn't able to include a photo in the Invisible Life piece because I couldn't find any to which I could get the rights. But here's a link to some nice images of Frankia to show you just how much they look like fungi, from their branched filaments to their sporangia bursting with spores. Remember -- these are bacteria. Not quite the textbook image of tiny, rod-shaped single cells, is it? You can read the Invisible Life Frankia piece here.

I also wanted to let you know about one other piece I contributed this week. If you've ever considered blogging or even felt a curiosity about it, The Open Notebook recently asked a few science bloggers -- including me -- why we do it. You can read our answers here.