Guest Author - Shane Hill
Let’s start by imagining your class on a regular Thursday after lunch.
It’s a comfortable sunny afternoon, your students are working with enthusiasm and a quiet focus has settled upon the classroom. You sit at your desk and across the room a beam of sunlight illuminates tiny particles floating in the air. It almost looks like an aerial display and you’re suddenly captivated by the interplay of two silvery spots. You drift into a slight reverie as you relax your gaze in the lovely warmth of the sun.
“Wasp! Wasp! Aaaaaaagh!!!”
The harmony of the moment is shattered as students shriek in terror and cower in their chairs while others leap to their feet and attempt to swat the wasp with rolled-up notebooks. Someone has already grabbed a can of bug spray and is unloading it’s entire contents into the air space of the classroom. The chemical stink rapidly fills the room and students begin to cough and wave their arms around. Mary McGregor is showing early signs of anaphylactic shock. Your delightful environment of calm and peace has transformed into panic and chaos with the addition of just one little six-legged visitor.
This scenario relates to the N.S.W. Curriculum Science and Technology unit Living World (ST2) and the food and farming units in the Australian National Curriculum. But while releasing a wasp into a classroom environment can help to demonstrate the interdependency of the environment and living things… and can be the catalyst for the entertaining expression of survival behaviours in juvenile human beings… there are calmer ways to look at interactions within an environment. It’s time to play Contamination Alert.
For this activity you’ll need ten ice cream tubs, one kilogram of dry red beans, two kilograms of white rice, 30+ paper cups and a broom and dustpan.
Nominate two students to be wild cats, four students to be birds and all remaining students are insects. Give each insect a paper cup and the wild cats and birds get the ice cream tubs.
Have the remaining four ice cream tubs in front of you. These represent the food sources for the insects. One tub is full of red beans, representing the “contaminated” (sprayed with pesticide) food source. The other three are full of rice, representing the clean food source.
Tell the students the container of red beans is a crop of food that have been sprayed with pesticide. However, there was a light breeze on the day that the pesticide was sprayed and some of the pesticide drifted to neighbouring farm-lands. Put a handful of beans into each of the three tubs of rice. Mix it through thoroughly then put the tubs around the room, in different locations.
The insect students are to ‘eat’ first. All students who are insects should go to any tub and take a pinch of food from that tub before moving on to the next tub. When their cup is half full of food they should stand where they are, dispersed around the room.
Now the birds are to eat the insects. Students who are insects hold their cup in front of them and move randomly around the room while the bird students move through them collecting the food from the insects, taking a pinch at a time from each cup of an insect student. When an insect student’s cup is empty, the student sits back at their desk. When all of the insects are sitting and the birds have collected all of the food, they stop and stand where they are.
Examine the bird’s tubs and explain what is being demonstrated. Discuss that despite the process being completely random, the insects may or may not eat poisoned food, and may or may not live as a result of the poison, but the chances of the birds getting the poison is much higher because they eat so many of the insects.
At the top of this food chain are the wild cats and now it’s time for them to eat. The wild cats stand and collect the food from the birds a handful at a time, gradually filling their tub. When the bird’s tubs are empty, they return to their seats and when all four birds are seated the wild cats put their tubs on a desk in the centre of the room and all students stand and gather in a circle around the tubs. Discussions here should centre on the fact that ALL of the food has been eaten and has moved through the food chain, which means all of the poison is now in either of the two wild cats.
Examine the tubs of the two cats to see which has the most amount of poisoned food. Then have the students redistribute the mixed food evenly between the four original tubs, the two wild cat tubs and the other four tubs. Place these 10 tubs around the room.
Now let’s skip forward to next year. Farmer Jones continues to use pesticide on his farm, which makes the land increasingly poisoned, so now Farmer Jones uses fertiliser to feed his crops and help them grow. The weeds love the fertiliser and grow quickly and the outcome is that less of the insect’s food-plants will grow.
In this new scenario, the red beans represent the food source. The rice represents other plant life such as weeds. Tell the students that nature is controlled by the seasons and the seasons are quite short, so the hunt for food is urgent. The two wildcat students are now insects and all of the insects must now hunt for 20 red beans, they can only take 3 beans from each tub and they have only 3 minutes to collect the 20 beans. If they do not get 20 beans, they die of starvation. Ready, steady, go!
The Insect students hunt for the red beans and after 3 minutes indicate clearly to the students that the time is finished. A big tubular train whistle which makes a loud and really great sound is an excellent way to end a period of busy activity. A whistle, bell or some other noise-making device is always preferable to shouting over the noise of a group of excited students.
Insects should stop searching for food but stay where they stand. Ask the insects to count their red beans. The insects who did NOT get 20 red beans have died of starvation and those students now return to their seats.
Fill some of the tubs with rice until four tubs are empty. The remaining insects should now move around the room as before and the birds use the empty tubs to walk around and collect the food from the remaining insects. Examine how much food each bird got and end the activity with any further discussions the impact of the pesticide on the food chain and the interdependence of animals living within an environment.
The Birds and the Bees is a wonderfully simple way to actively and very vividly show the dynamic relationship between an environment and the organisms living in the environment, while also showing the potential impact of harmful substances on that environment. Interdependency is demonstrated via the food chain model and this can be expanded upon if desired by including other different coloured beans or legumes to represent other creatures and the impact of their presence or absence on the food chain.
The game does not make use of teams or scoring or even a sense of competitiveness yet the game itself is compelling for the students because of what their actions represent. A high degree of trust is required in the execution of this game, in terms of students taking only three red beans from a tub, and the presence or lack of students adhering to this rule can itself lead to conversations about behaviours of animals in the natural world.