Do we know about crustaceans? They are arthropods. We eat
some of these creatures, and consider them delicacies. Crabs, shrimps, and lobsters are crustaceans; so are water fleas. What characteristics do they have in common? Crab, shrimp, and lobster feed on the floor of the ocean. I don't know where water fleas go for dinner, nor do I know what they ask the waitress to bring them.

Generally, crustaceans live in water, have two pairs of antennae, have one pair of legs for each body segment, and hatch from eggs laid in water. Barnacles are crustaceans. So are crawdads (crawfish).

I didn't know that barnacles had any legs at all. I thought they just stuck onto the sides of whales and ships, and rode along wherever they went. The Columbia Concise Encyclopedia defines barnacle as: "Sedentary marine animal (subclass Cirripedia), a crustacean. Barnacles permanently attach themselves to a substrate by means of an adhesive cement. They secrete a calcareous shell around themselves and form conspicuous encrusting colonies on rocks, pilings, boats, and some marine animals, such as whales and turtles. The attached end of the animal is the head; jointed legs (cirri) sweep food particles through the shell opening to the mouth. Some barnacles lack shells and are parasites of other invertebrates." Well, now I see that barnacles do have legs and what those legs do. They aren't for cruising around the sea floor. They do the things for which we use hands.

Sowbugs are land crustaceans found in dark, moist environments, under boards, logs, and stones. They are related to pill bugs and wood lice. Pill bugs will roll into a ball when touched, but sowbugs will not.

The sowbugs you capture can be kept in almost any type of container. Of course, you want to be able to observe them, and that's kind of difficult if you put them into a can or box. You can make a woodland environment for them in a fish bowl with some soil, small sticks, dead leaf material, and small rocks. They will eat very small bits of apple, lettuce, raw potato, bread, and small insects. They are fun to watch.

What do you think is their main job? We have observed that there appears to be a job that each creature does. Sometimes it is easy to figure out what their job is. Sometimes not. We'll have to discuss nature jobs at some time in the future.

When I look in the dictionary and encyclopedia for these things, I see the words, "class," "order," "subclass," "species," "subspecies," "phylum," and other terms that refer to groupings. We will have to look into those group terms.