It's enough to make your skin crawl: the thought of living one's life
completely surrounded by bugs and bacteria. Some of these organisms live
off of the structure of your house, gnawing, digesting, and converting
to sawdust what was once a solid structure. Other organisms live on your
pets, especially in their furry coats. And, believe it or not, countless
organisms -- in fact, billions of creatures -- live on the surface and
inside of your body, most of the time without your knowing.
How do all these uninvited guests go unnoticed? Although many of these
organisms live out in the open -- on the back of your hand, for instance
-- most are simply too small to be seen. No matter how carefully you
look, it is impossible to see the dust mites and bacteria that inhabit
your skin without the aid of a microscope. As for the larger organisms,
including carpenter ants, termites, silverfish, and a host of others,
these creatures are notoriously good hiders, staying concealed for most
of their lives or coming out only under cover of darkness.
It may be uncomfortable to think of your home and especially your body
as habitats for other animals, but that's exactly what they are. These
organisms share our space for the same reasons other animals live in a
forest ecosystem or a river ecosystem: because they find food and shelter
there. Wooden window and door frames provide protection and food for
carpenter ants and house borer beetles, just as our skin and digestive
system provide the same for mites and bacteria.
most of the creatures that use our homes and bodies for habitats are
relatively harmless. In fact, some of these organisms provide a service
to us and our environment, much like the role decomposers play in a
forest ecosystem. Dust mites, for example, consume the dead skin cells
that our bodies slough off at a rate of about 1.5 million per hour. In
turn, our discarded cells provide the mites with an energy-rich food, one
that might otherwise go unused. Bacteria in our stomachs and intestines
also help us to break down food that is difficult to digest and also
fight off harmful bacteria that invade our bodies.
course, knowing the good these organisms do doesn't make them any more
welcome. But the next time you feel creeped out by what's crawling on
your dog, just remember he could say the same about you.