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Did you do the tree leaf age experiment last spring to see how long tree leaves stay on the tree? Now would be a good time to check your trees. Let us know what you found out so far. Some of the leaves we marked on our orange tree last spring are still on the tree.

If you live where trees are deciduous, you might want to study the next step:  what happens to leaves when they fall off the tree?

First, think about and make a list of what you think might happen. Do you think some might be eaten, or that they will all blow away?

Scientists study the decomposition, or breakdown of leaves, by putting leaves in nylon mesh bags and letting them sit on the ground for long periods of time. The researchers come back every few weeks and pick up a few bags to take back to the laboratory. They open the leaf bags up and see what is happening. They look at things like how much weight the leaves lost, what kinds of critters have been eating the leaves, and how the leaves have lost chemicals (nutrients) over time.

You can make your own leaf bags (also called litter bags).

Gather:

  • Heavy duty screen door nylon mesh (1 x 2 mm mesh size is best) or the nylon mesh bags that fruits or onions come in from the grocery store.
  • Equipment, such as scissors, for cutting screen mesh
  • Equipment for closing the screen bag: glue gun or sewing needle and thread (soldiering irons can be used by adults).
  • Place you can safely leave leaf bags under trees and be able to retrieve them over time

If you are using the pre-made nylon bags from the grocery store, you can skip this step. If you are using screen door mesh, cut out strips 10 inches (25 cm) wide and cut into 8 inches (20 cm) sections and fold in half. Use the glue gun, needle and thread or soldiering iron to seal two sides. Leave one end open so you can put the leaves in.

Once you have the leaf bags made, go outside and fill them with leaves. Try to use freshly fallen leaves and collect only the leaves from under the trees where you will be leaving your bags. If the leaves are too dry, you can wet them with a bit of water to get them into the bags without crumbling. The grocery store bags will have larger openings, so you might want to use bigger leaves.

Close the bags with hot melt glue, or by sewing or tying them shut. Place the leaf bags outside in a place where you can safely retrieve them. You might consider marking the bags with sticks in the ground or tying the bags to brightly colored tent pegs shoved into the ground.

Now you have to be patient. Check the bags roughly every month and see how they are faring. Leave them under the trees until next year and then be sure to collect them. Open the bags into a tray or pan and sort through the contents. What do you think you might find?

Other fun activities for fall leaf drop season are to put the leaves back on the tree and exploring fall color.

Do you know what kind of tree this is?

We'd love to hear what you find in your leaf bags.

Edit: I just found three awesome ideas for using fall leaves at 5 Orange Potatoes. The first is laminating leaves to make leaf rubbing plates. The second is a game called odd leaf out. The third is making polka dot leaves.

Pill bugs, rolypolies, wood lice, potato bugs or isopods, these cute little crustaceans come with a bunch of common names. Add the names for their close cousins the sow bugs (the ones that can't roll up) and the shore isopods called slaters, and you have a dictionary full.

What do you call these seashore isopods?

Today we're going to be using pill bugs, the ones that look like a pill when they roll up.

Although most people associate pill bugs with moist environments,  surprisingly we have pill bugs in the desert that can tolerate a much drier climate. They are common and active residents of our back yard, although they do seem to prefer the irrigated areas.

Pill bugs are fun to investigate.  First, prepare a temporary holding container with a walnut-sized wad of moist paper towel and a few bits of carrot for food. Look outside under stones or logs for pill bugs. Note:  always return the rocks or logs to their original position when through, and be careful if you live where there are poisonous critters that live under rocks. You might want to tip them with a bar.

When you find some pill bugs, gently transfer them to the container. After they unroll, you can look at them through a magnifying lens. Study how they move and their body parts.

Check the "Using Live Insects in the Classroom" Isopod Information Sheet for a detailed description of their morphology.

1. Draw or build a model pill bug.

Gather materials such a paper, cardboard, chenilles and/or clay and create a pill bug model. Pay particular attention to what they look like, because the more details you add, the more realistic the model will be.

2. Do all your pill bugs look alike? We found some of ours were entirely dark gray whereas others had gold or yellow spots on their backs.

Any ideas why pill bugs might be different colors?

3. When the pill bugs roll up, can you still see their antennae? Our desert pill bugs can roll up with their antennae inside, other species can't. Why might that be?

4. Build a simple maze and test some of your ideas about pill bugs. We built ours out of light cardboard, like a cereal box. We taped it down with masking tape so it wouldn't fall on the pill bugs. Be careful that no sticky edges are exposed, because the pill bugs might get stuck. We also found certain pill bugs wouldn't cross the masking tape, so try to keep the tape on the outside of the maze. While planning, you might want to sketch your maze on graph paper or use a computer.

We tested the idea that pill bugs would prefer darkness to light. We also offered them different types of food.

In the video, we wondered if the pill bugs would explore a complex maze with a lot of turns to find food. We set two pill bugs in the maze entrance together. See what happened:

We had fun and learned a lot about how pill bugs behave. Hope you give it a try.

Once we were done, the pill bugs went back to nature unharmed.

For more information and great science activities with pill bugs, I highly recommend:

Rolypolyology (Backyard Buddies) by Michael Elsohn Ross, and illustrated by Darren Erickson

It seems to be out of press, but you should be able to find it at your local library. It is filled with fantastic ideas.

Other pill bug books (linked images and titles go to Amazon):

A Pill Bug's Life (Nature Upclose) by John Himmelman

The Pillbug Project: A Guide to Investigation by Robin Burnett

I'm a Pill Bug (Nature: a Child's Eye View) (Nature: a Child's Eye View) by Yukihisa Tokuda, and illustrated by Kiyoshi Takahasi

Nature Close-Up - Pill Bugs & Sow Bugs and Other Custaceans by Elaine Pascoe

Pill Bugs Up Close (Minibeasts Up Close) (Perspectives) by Greg Pyers

Compost Critters by Bianca Lavies is an excellent introduction to composting. Although it is an older book, the photographs are excellent.

Previous post on pill bugs

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Because we were eager to participate in International Rock Flipping Day, we peeked under some rocks in our yard this morning.

Flipping rocks was somewhat disappointing at first. It has been the third driest summer on record in central Arizona, and because the summer is when we normally get most of our precipitation, we are really dry. The terms dry as a bone, parched, and desiccated come to mind.  Most of the rocks we looked under would normally have isopods (rolypolies), ants or earwigs, but we didn't see any of those. Occasionally we might see a scorpion. We didn't see any of those either.

What we did find was this:

Any ideas what might cause these white tunnels? I'll give you a hint:  it isn't a type of spider, although it is made of silk.

In fact, the tunnels are made by an insect. Here are some photos I took of one earlier this summer.

Does anyone remember what it was?

(If you want to find out the answer, check this previous post.)

All in all, we saw something we wouldn't have otherwise seen, and realized how much the lack of rain is changing the environment for even tiny things that live under rocks. And best of all, we got outside and had some fun.

What did you find?