Alternate Activity 3: Log Dissection
Activity time: 20 minutes
Materials for Activity
- A partly decomposed log, approximately 1 to 1.5 feet long and at least 8 inches in diameter
- A can opener, a bottle opener, or a knife large enough to open the log (for adult use)
- Magnifying glasses
- Optional: Newspaper or a tarp
Preparation for Activity
- Select a location, preferably outdoors, where everyone can see the log. If indoors, place the log on the newspaper or tarp.
- Optional: Familiarize yourself with the creatures and plants you are likely to find on and inside the log. The Smithsonian National Zoological Park offers a useful extension activity online, "Is There Life in a Decomposing Log?", which suggests a variety of books and websites, and includes a link to a "virtual rotting log."
Description of Activity
This activity is best done outside, but you can keep the log on newspaper or a plastic tarp and do the activity inside.
Observe the outside of the log with the children. Look for moss, bracket fungus, lichen, and other living things. Ask:
- Do you see any insects crawling around?
- What are they doing?
- Are there white patches or streaks? (That may be mold.)
Now ask the children what they think the inside of the log might look like. Use a can opener, bottle opener, or a knife to open up the rotting log. Observe what you find.
Have the children feel the bark gently as well as the inside of the log (do this carefully making sure there are no biting insects such as centipedes). Notice places where the wood is spongy and soft, notice others where it is crumbly. Sniff the rotting log. Ask:
- How does it smell? Moist? Earthy?
- Does it smell like something rotten or more like good garden soil?
See what kinds of critters you find inside. Explain that bacteria and fungus are the main decomposers, but insects such as beetles, maggots, and ants help break up the bark and wood and allow more air (oxygen) in.
Hand out magnifying glasses and allow the children to get a closer look at the hidden life inside the decaying wood.