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National Geographic Invaders (Part of the Strange Days on Planet Earth Series)

Grade Level: 6-8

Time Frame: Two, 40-45 minute class periods  (could also be carried out in science class if it works better in your school).

Introduction to Lesson: 

In this lesson, students will watch the "Invaders" episode of the National Geographic Series "Strange Days on Planet Earth".   This documentary addresses many of the ideas about invasive species that have been covered in this learning unit but uses different examples to those we've looked at so far.  Watching and thinking about the video and then researching Phragmites and other invasive species as assigned by the teacher will provides the students with the opportunity to extend their understanding of the impact of invasive species by looking at a variety of invasive species around the world and the problems that they cause.  It will also provide them with the opportunity to research simple things that they and their families can do to help reduce the chances that things that they do will introduce additional invasive species into their neighborhoods and local wild spaces.

Image source:

New Jersey Core Curriculum Content Standards: 

STANDARD 3.4 (Listening) All students will listen actively to information from a variety of sources in a variety of situations.

Active Listening

  1. Demonstrate active listening behaviors in a variety of situations (e.g., one-on-one or small group).
  2. Demonstrate active listening by analyzing information, ideas, and opinions to determine relevancy.

STANDARD 5.10 (Environmental Studies) All students will develop an understanding of the environment as a system of interdependent components affected by human activity and natural phenomena.

Human Interactions and Impact                                                                                        


Describe the effect of human activities on various ecosystems


Evaluate the impact of personal activities on the local environment.

STANDARD 6.1 (Social Studies Skills) All students will utilize historical thinking, problem solving, and research skills to maximize their understanding of civics, history, geography, and economics.

Social Studies Skills.

bullet Use critical thinking skills to interpret events, recognize bias, point of view, and context.
bullet Assess the credibility of primary and secondary sources.
bullet Analyze data in order to see persons and events in context.
bullet Examine current issues, events, or themes and relate them to past events.
bullet Formulate questions based on information needs.
bullet Use effective strategies for locating information.
bullet Compare and contrast competing interpretations of current and historical events.

STANDARD 9.2 (Consumer, Family, and Life Skills) All students will demonstrate critical life skills in order to be functional members of society.

Critical Thinking

bullet Communicate, analyze data, apply technology, and problem solve.
bullet Describe how personal beliefs and attitudes affect decision-making.
bullet Identify and assess problems that interfere with attaining goals.
bullet Recognize bias, vested interest, stereotyping, and the manipulation and misuse of information.
bullet Practice goal setting and decision-making in areas relative to life skills.

 Interpersonal Communication

bullet Demonstrate respect and flexibility in interpersonal and group situations.
bulletOrganize thoughts to reflect logical thinking and speaking.
bulletWork cooperatively with others to solve a problem.
bulletDemonstrate appropriate social skills within group activities.
bulletPractice the skills necessary to avoid physical and verbal confrontation in individual and group settings.
bulletParticipate as a member of a team and contribute to group effort.


bulletA copy of the "Invaders" episode.  This episode is available free on line at and at  Alternately, look for this excellent show as part of a 2 DVD set at your local library or have your school purchase the set from PBS for $25.
bulletStudent Worksheet for the Movie (MSWord Format, Pdf Format)
bulletTeachers' key and optional word bank for use with special needs students, if desired   (MSWord Format, Pdf Format)
bulletGroup Worksheet for the Invasive Species Management Activity (MSWord Format, Pdf format)
bulletAccess to computer lab or printouts of selected invasive species factsheets from websites in list provided.
bulletIf poster / powerpoint presentation is created at the end, access to computers or suitable art supplies will be needed.

 Objectives:  After completing this lesson SWBAT


Describe some of the ways that invasive species are transported into new habitats


Describe some examples of invasive species and the harm that each causes


Explain how damage caused by invasive species can often impact those already at a social disadvantage and discuss how this makes combating invasive species a social justice as well as an economic issue


Explain why invasive species are more of a problem today than ever before in this planet's history


Describe some things that they and their families can do within their yards and communities to help slow the number of new invasive species that enter natural habitats here in the USA

Anticipatory Set:  This lesson is designed to be part of a capstone experience for this unit.  By this point the students should have explored the issue of invasive species in a number of classes, particularly in the science portion of the curriculum.  We thus suggest starting this lesson by asking students to name the invasive species that they are aware of, either from listening to the news or watching TV or from exploring materials in other portions of this learning unit.  The obvious answer (we hope!) will  be Phragmites (the common reed).  However, other species mentioned in materials assigned for this unit include gypsy moths (many NJ students will be personally familiar with these since an outbreak of these animals in 2008 removed leaves from many trees especially in Jackson Township and stories about them were in the media for much of the summer of that year), Wooly Adelgids, Asian Longhorned Beetles, Canada Thistles and kudzu.  Recent news-making invasive species include Japanese shore crabs, Chinese mitten crabs, snake head fish, Japanese stilt grass,  Asiatic bittersweet and mile a minute weed.  When a student names an invasive species, engage that student and others in a discussion about that species.  What do they know about it?  (what kind of animal or plant is it, why is it bad etc?).   Conclude the discussion by telling students that today they will be watching a movie about invasive species and their impacts on people's lives as well as on natural ecosystems.

Sequence Instruction:

1.  Teacher and students will watch the "Invaders" episode of the National Geographic Series "Strange Days on Planet Earth" together.  As noted in the materials section of this lesson plan, this episode is available free on line at and at  Alternately, this excellent show is often available as part of a 2 DVD set from your local library or for purchase from PBS.

To help keep the students on task during the movie, a worksheet (MSWord Format, Pdf Format) is provided. 

Once the students have viewed the episode (or in the next class), split the students into teams and assign each team to research one of the invasive species in the list below.  Several links to key fact sheets are provided for each species.  If students are using the computer lab they can look for additional resources, but if a computer lab isn't available teachers can provide print copies of the suggested links and the information therein should allow the students to answer most or all of the assigned questions:

Japanese knotweed
Eurasian Water Milfoil
Japanese stilt grass
Gypsy Moth
Wooly Adelgid
Japanese Shore Crab
Chestnut Blight
Dutch Elm Disease
Asian Tiger Mosquito

Questions to answer regarding student group's assigned species (a worksheet for this exercise is provided in the materials section above).

1.      How did your assigned species arrive in the US?

2.      How does it spread from one place to another now that it is here?

3.      Why is your species a problem?  (what damage does it do)?

4.      Brainstorm:  What are the likely social consequences of this invasive organism?  (answers will likely NOT be on the sheets:  students will need to think about this for themselves and will likely need help from the teacher who should walk around between the groups during this phase with suggestions and hints as needed).

(e.g.  when Phragmites invades wetlands the wetlands dry out.  This means that they no longer function as filters for pollutants, and so drinking water may be more polluted when it comes through invaded areas than it was after passing through the pre-invasion wetland.  Since wetlands also help absorb water after rainfalls, they help prevent flooding.  Invasion by Phragmites may thus mean that people in low lying communities downstream of the invaded marsh may have a higher risk of flooding during storms.  The loss of the esthetic value from invaded wetlands (less variety of flowers, birds and animals, less pretty blue open water etc.) also has a social cost in lost recreational / spiritual value of our wildspaces).

5.      Develop a list of management methods that can be used to reduce the size of the populations of your assigned invasive species in the US?

6.      Which of the methods that you have listed are mechanical?  Which are chemical and which are biological?

  1. Mechanical controls use physical methods for removing invasive species.  For example cutting down or digging up an exotic plant, physically picking up or trapping and removing an unwanted animal species or removing something it needs for its life cycle (e.g. removing a pool of standing water needed for a species to breed in).  Placing nets or fences to keep an animal in or out of a specific habitat would also be an example of mechanical control.  Such mechanisms are often very labor intensive (it takes a lot of work to dig up an invasive plants for example) and take a long time, and many repetitions of the treatment to start to work (digging up survivors, removing standing water over and over again etc). 
  2. Chemical controls use application of chemicals such as herbicides (kill plants) and pesticides (kill animals or prevent them from reproducing) to remove invasive species.  They can also involve using pheromones (the chemicals that animals use to attract mates) to lure target animals into traps.  Because it is easier to spray something than to dig it up, these methods tend to be more practical when working with larger populations of invasive species.  They also are often more effective, so the species may be effectively removed by one or two treatments, whereas mechanical methods may take much longer and many more repeated applications of the method to be effective.  Unfortunately most herbicides and pesticides donít just kill the target species. They may thus kill native species living near the target invasive species.  The chemicals used can also be carried by water or air currents into nearby ecosystems such as lakes, bays and the ocean, and, if they are present in sufficiently high concentrations there, they can threaten the health of the plants and animals (including humans) in the area. Another problem with chemical controls is, if the chemical is used for a long time, the target species often develop a resistance to the chemical being used to kill them, and so the methods often stop working or work less well after a while.  
  3. Biological controls refer to the release  of living organisms into a habitat to fight invasive species.  These organisms are usually predators that eat the problem animal or plant, but sometimes may be bacteria, viruses or other disease-causing species that get rid of the invasive species by making it sick.  Another strategy is to introduce sterile members of the species that can mate with other members of the invasive species to make eggs that either don't develop, or which produce young that are themselves reproductively sterile. The good news here is that there are no poisonous chemicals here and you're not digging up or otherwise changing the habitat to get rid of the problem species.  Of course the bad news is that you have to pick the species that you use to control the invasive species carefully so that it only eats / makes sick the target species.  Otherwise the species you introduce may start eating native species or making them sick too and now you have another problem species that needs to  be controlled itself.  Other problems with biological controls is that the species introduced to control the invasive species may have a hard time surviving in that habitat and so they may not last long enough to effectively wipe out their targets.

7.      What are the ADVANTAGES and DISADVANTAGES of the management strategies youíve found for your species?

8.      What methods might be used to PREVENT the further spread of your assigned species (or is this irrelevant for your species? If so why?)

9.  If desired have students create a presentation about their chosen species to the rest of the class.  Depending on resources, this presentation could take the form of a poster, PowerPoint or even a skit in which the students play act members of a community that has just found out that their assigned species has arrived in their communities and the community tries to understand how it got there, how it will spread in their communities, why its bad and what they can do to either eliminate it from their community or prevent it from spreading further than it already has.

Exit Activity: Have the students write on a slip of paper one or more thing that they think is happening in their neighborhood that might create the risk of introducing new invasive species into native habitats and one thing that they, their families, friends or neighbors could do to help reduce this risk.

Assessment:  Teachers can use students' worksheets to assess their attentiveness during the movie and their comprehension of its content, as well as their work within their groups.

Additional Resources:


National Geographic Offers a Number of Associated Resources to support teachers working with the "Strange Days" series:


It also offers an additional lesson plan that integrates science, social science etc. as students role play various decision making scenarios


And another lesson plan that allows students to investigate "America's Most Wanted" invasive species


An additional Associated Lesson Plan on Identifying Invasive Species within the Students' local environment is available at


What would you do?  A lesson plan that has students create a management plan for a given exotic species after investigating that species and the available management options.


TEACHER FEEDBACK REQUEST:  We are always to working to improve these lesson plans. If you use this lesson plan, we'd love to hear from you with your thoughts, comments and suggestions for future improvements.  Please take the time to fill in our survey at .  Thanks!

© 2009.  Allison McGrath (Author of worksheet), Louise Wootton (Author and Editor)

 Although the information in this document has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement NE97262206  to Georgian Court   University, it has not gone through the Agency's publications review process and, therefore, may not necessarily reflect the views of the Agency and no official endorsement should be inferred.

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