Grade Level: 6 - 8
Subject Matter: Life Sciences
National Standards: NS.5-8.1, NS.5-8.3
Images of various “bugs” such as spiders, centipedes, flies, etc. (must include several insect images)
1 – 2 dozen live crickets (available from most pet stores)
Cricket habitat (plastic or glass aquarium)
Transparent plastic cups
Plastic food wrap
Cricket food (available at pet store)
Cotton balls soaked with water
Empty paper towel tubes
Insect: A small, usually winged invertebrate with three pairs of legs and three distinct body parts (head-front, thorax-middle and abdomen-back).
Arachnids: a class of animals that includes spiders, scorpions and mites.
Exoskeleton: hard covering on the outside of an insect that provides support and protection.
Spiracles: a tubular system in insects or spiders that allows air to enter and exit the body.
Ovipositor: a tubular organ at the end of the abdomen that is used to deposit eggs.
Cerci: paired appendages at the end of the abdomen that serve as sensory organs.
Compound eyes: eyes that consist of several separate light-sensitive lenses.
Palp: a sensory appendage near the mouth used to assess or manipulate food.
Tympanum: a vibrating membrane in some insects that serves as a hearing organ.
Reappraisal: evaluating a judgment or opinion.
Prep: Before you present this lesson, become familiar with the anatomy of a cricket by researching and viewing diagrams or images online or at the library. Teachers TalkingScience recommends that you hand out to your students printed copies of a diagram of the parts of a cricket’s anatomy that are explored in this activity. Or you can draw a sketch, based on your research, on a blackboard.
1. Start the lesson by having students watch the SciFri video, “Psychological Reappraisal of Bedbugs”. Hand out science journals or notebooks and have students write what they know about insects. Students should concentrate on only writing science facts that they think they know about insects such as body parts, what they eat, where they live, etc. Now ask students to write their emotional responses to insects. Do they have any insect phobias? Discuss their responses with the entire class.
2. Hand out the images of various types of bugs. Instruct students to sort the images into two piles one for “insect” and one for “other”. Have students examine and discuss the differences between the images once they have completed sorting. What similarities can be found in the insect pile? What are the differences between an insect and an arachnid? Students should write their explanations in their journal.
3. Ask students to focus on the image of the cricket. In their science journal, have students write observations from the image (body parts) and also how they feel about crickets.
Activity 1: Cricket Anatomy
Prep: Before this activity, prepare the crickets for student observation. Place one cricket inside a clear plastic cup, cover with plastic wrap and secure the plastic wrap with a rubber band. Use a needle to poke small holes for ventilation. Prep enough crickets for each student or for each group of students.
1. Hand out magnifying lenses and crickets to students. Ask students to observe the cricket and explain why a cricket is classified as an insect. Students should write their explanations in their science journals as well as any observations throughout this activity.
2. Have students locate the head of the cricket. This is one of the main body parts of a cricket. What features do they see in the head area? How many sensory organs can they observe?
3. Have students locate the second main body part of the cricket, the thorax. What appendages are connected to the thorax? What function does the thorax perform?
4. Have students locate the third main body part, the abdomen. What physical features can they observe that extend from the back of the abdomen? All crickets will have two short hair-like body parts extending from the back of the abdomen. These are called the cerci. What do they think is the function of the cerci?
5. Ask students if they are able to distinguish a male cricket from a female cricket. Tell students that males and females of any species usually have some type of different body feature from one another. Have students go around the room observing other crickets to see if they can observe any differences that would distinguish a male from a female cricket. If necessary, hint that this distinguishing feature is located in the abdomen area.
6. Have students examine their cricket and raise their hand if their cricket has a long tube-like body part extending from in between the cerci. Tell students that this appendage is called the ovipositor and is only found on the female cricket. What do they think is the function of the ovipositor?
7. After completing observations and journal entries, have students carefully place their crickets back into the cricket habitat.
Activity 2 - Cricket Care
1. Create a classroom chart that assigns groups of students to make daily observations and care of the crickets for the next week. Besides feeding and watering the crickets, students should also make observations at regular intervals four or more times per day on the chart. Students can determine what type of data should be collected or select from the following list:
- Are crickets chirping?
- Are crickets eating?
- Are crickets drinking?
- Are crickets interacting with each other?
- Number of females alive.
- Number of males alive.
- Number of crickets jumping.
- Number of crickets sitting still.
- Number of crickets hiding in tubes.
2. After one week of caring and observing for the crickets, have students review and discuss the results from their chart. Were the crickets chirping at a certain time during the day? How many times a day did they eat? What conclusions can they state based on the data collected?
3. Discuss with students how they feel about crickets after caring for them compared to their initial feelings at the start of the activity. Did any of their feelings towards crickets change? Do they think that by taking care of the crickets they “reappraised” their negative feelings towards crickets?
- Why do crickets have so many sensory organs?
- How is a crickets anatomy different than that of a human or another animal?
- What are other physical differences between male and female crickets?
- Explain the relationship of crickets in the food chain.
- What are some physical features on a cricket that assists in its survival?
Raise and breed crickets as a classroom project so that students can observe the life cycle of a cricket. Students can research methods to maintain long-term cricket habitats and track the stage of a cricket’s life cycle.