What You Don't See

A cool biology experiment is included in this article!

You can't see them and they are so small that you can't even feel them. They function as all living things, taking in food, water, gases; they excrete waste, change when the environment changes, grow, and even reproduce. These tiny organisms share the characteristics that all animals possess including mobility, sensory organs, and the ability to eat. Although they are invisible to the naked eye, once they are flashed under the eyes of a microscope they immediately become visible.

The smallest of microscopic animals are called protozoa and include the Amoebae, Paramecium, Stemtor, and the Vorticella. These invertebrates are generally a source of food for small fish and they are essential in the animal food chain.

When you peer at Protozoa through the microscope, some appear round with little hairs fraying around them like lost willows. Some exhibit whip-like tails that wiggle back and forth. Imagine what these guys could do with a little Elvis music!

Mosquito larva is another unseen organism that could be lurking as close as your backyard. They tend to like standing water and stagnant ponds.

Fleas are tiny organisms that are very difficult to detect with an unaided eye. These bloodsuckers thrive on wildlife. Things can get very ugly when they make rats their haven of rest.

Mites are tiny, eight-legged animals, measuring less than one-twentieth of an inch. One species, known as the scabies mite, lives solely in the human skin. It will actually burrow into the skin and create an intense itch.

The house-dust mite generally makes its home in bedding. Sometimes these mites can attribute to asthma when the dead mite parts and dust are inhaled.

Chiggers are another type of mite and inhabit grassy areas and crops. Their bite can produce an ugly itch that forms a rash. Mites that thrive in grain or fruit can cause grocers' itch or bakers' itch, a type of skin irritation.

Student's Biology Project

You will need the use of a microscope for this project.

Carefully collect some water from a local pond using gloves for protection. Remember the old adage, 'It's what you can't see that can hurt you'. Be sure to use a sealable, clean container for the water.

Place a drop of the pond water on a slide and view under a microscope. Ask the student to draw pictures of the organisms. Place a bit of fine hay or wheat in your bottle of pond water, then wait a few days before examining. You will find an entire collection of new little animals have joined the force.

If you would like to stretch your project, collect water samples from other sources such as snow, rain puddles, mud puddles, even from your kitchen sink. Compare them with the pond water sample.

Different substances can be introduced to the culture including flowers, leaves, honey, and milk.

Reference: Nature Through Science & Art by Susie Gwen Criswell