Structure and Process Grade 4

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ENGAGEMENT

Have you ever seen a sci-fi movie with giant insects or spiders? There are every sort of invasion or menaces by spiders, ants, scorpions, beetles, mantids..you know an insect, there's probably a monster movie. Here are some cheesy examples:

 Giant spider on Kong Island

 Flesh eating beetles in The Mummy

 Giant mantids in The Praying Mantis

  Giant Moth, Mothra

  The Fly

Ask students what films they have seen that have insects or spiders in them. There are lots!

So you won't have to watch too many, here's a clip of a cheesy 50's flick, like THEM!  

Ask students why we might be interested to know something about insects based from their own experience and from the example/s used above. What would it be like to have a giant insect next door?

EXPLORATION

Why do we think some insects would be harmful if they were large and our size or larger? Brainstorm a list of things that could be a problem if insects/spiders were our size or larger:

* They might eat our food ( a giant grasshopper could eat a whole tree!)

• They might eat us! ( a spider or carnivorous beetle could chomp us down!)

• A stinger on a wasp, scorpion, bee could kill!

• A mosquito would have a giant hypodermic needle--what a bump!

• Predatory insects and spiders may prey on our domestic animals. 

• Herbivorous insects could burst into Safeway and eat the produce aisle!

• Insect jaws would be huge

• Insects could interfere with airplanes

Use diagrams to help your students vision an extra large creature. (Leg, stinger, eyes, jaws below)

Part I 

Depending on the age group you might be dealing with, select any of the following organisms for exploration:

    • Mealworm adults

    • Sow bugs

    • Crickets

    • Roach nymphs

    • Wax worms

    • Soldier Fly larvae

    • Ladybugs

1. Provide students with a petri plate and a few organisms and a hand lens.  Ask students to observe their insect/bug.  

2. Provide drawing paper and pencils to sketch the details of their creature. 

3. When they have completed their observations and drawing, provide a biological description.  Good diagrams are provided in pdf as follows:   Beetle,  Sowbug, Crickets, Roach nymph, Ladybird Beetles

4. Have students see what they missed in their observations and invite them to look again to see details.

ASSESSMENT

A rubric can be used to check students for proper labeling of their diagram or a simple check sheet can be used if students draw and label the correct parts.

Materials List for part I

• Insects in petri plates

• Hand lenses

• Drawing Paper

• Pencils/colored pencils

Part II

1. Give students materials to model their chosen insect.

Exploration: Making a solid model.

Here is a quick video overview:

Here is a step-by-step process:

1. Find materials that can be easily connected with a glue gun.  Corks, wooden balls, chunks of foam, plastic pieces, stiff wire, pipe cleaners--an assortment of things students could use to model an insect.

2. Find a piece of dense foam for the thorax. Push wires through to make legs as shown

3. Using stiff wires (they can be copper, iron, or aluminum--but not pipe cleaners) bend three into "U'" shapes and stick them through the holes. Glue underside of wires to hold them in place:

4. Add a head and abdomen by gluing to thorax.

5. Add antennae by gluing pipe cleaners onto head. (Pipe cleaners are a good analogy because they are textured--insect antennae are sensory) . 

6. Add a compound eye by dotting the head with a marker.

Assessment

Like the drawings, the models may be evaluated for appropriate structures. Ket to this exercise is whether students use the language as they build. Check for understanding as you ask students what parts they are assembling such as, "What part are you using for the thorax?"

Materials for Part II

• Round balls

• Foam chunks

• Corks or dowels

• Flexible wires

• Needle nose pliers

• Glue gun

• Scissors or utility knife

• Pipe cleaners

• Felt pieces

PART III Animatronics

7. The insect is now ready for action!  An AA cell, a switch and a vibrator motor out of a cell phone can be connected as follows:

The motor has an unbalanced weight on the shaft that wobbles when it runs. These kinds of motors, many kinds of switches and AA cells and holders are readily available through electronic warehouses such as www.goldmine-elec-products.com/  and ebay.

 Slide switches are easy to use and cheap (usually less than 20 cents each

Miniature vibrator motors often come with two wires already attached. About $1 each. You can substitute a regular tiny hobby motor and add a weight to the shaft to achieve the same effect.

Cell holders are a little less common, but can be found on eBay for about $1 each.  You can also solder wires directly to the cell and avoid this cost, or use a sturdy rubber band to hold the wires onto each end of the cell.

7. Glue the motor to the abdomen of the bot.  

8. Add the battery and switch

9. Depending on how you position the motor and bend the legs, your bot will either travel in circles, go backwards, or go forwards.  It can travel rather quickly if the motor actually touches the surface lightly.  

Assessment

Are the students tweaking their system?  This is what you check for--adjustments, observations, and manipulation of the system. Pictures, video and audio clips give the best story from what students say and do.

Materials for Part III

• Model insect

• battery, switch and motor circuit

STEM CHALLENGE

I. Your insect bot is larger that the actual bug. How much larger? What scale is it (like train gauges that are ratios of the actual size of a train).  Is your insect 2X, 5X, 10X as large as the real insect? How can you tell?  Once you have a scale, then compute the speed of your bot.  How fast is your insect?  How does that compare to the speed of the real insect?  How about the ant in the movie? Did is move too slow or too fast for its size? How can you tell?

II. Battle bots are designed to do damage to each other. Engineering students use these kind of challenges to design impressive machines that can avoid injury and impart mayhem!  The insect bots that we have made here can be modified so that when a bot is hit by another bot, a switch can be activated turning the bot off.  How can the bot be modified to add a "kill" switch so that the skittering bots can stop one another?

2. The parts can be named and the basic functions can be discussed:  

    Head: 

        antennae (feeling and taste)

        Compound eye (shapes and color)

        Ocelli ( light and dark)

        Mandibles (chewing)

        Sucking mouthparts 

        Palps (taste and feeling)

    Thorax: Movement:

        Legs, tarsi on legs, femur , tibia

        Wings (some with 2/4/none)

        Wing covers (beetles and Hemiptera

          Tympanum (ear)        

    Abdomen

         Respiration (holes [spiracles] on sides)

         reproduction (ovipositor

         digestion (gut inside abdomen)

Part III

Project Learning Tree/Project Wild Extensions

PLT, p. 23. Peppermint Beetle

PLT, p. 105. The Fallen Log

PLT, p. 108 Nature's Recyclers

PLT, p. 194. Web of Life

PLT, p. 197. School Yard Safari

PLT, p. 200, Are Vacant Lots Vacant?

PLT, p. 263, The Closer You Look.

PW, p. 4, Grasshopper Gravity

PW, p. 12, Interview a spider

PW, p. 34, Spider web Geometry

PW, p. 88, Ants on a Twig

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