NATURE

The Trial of the Bloody Sucker
Subject: Life Science, Geography
Grade Level: 4-6

The NATURE episode BLOODY SUCKERS investigates the organisms that live off the blood of others. Some of the organisms are painted as being dangerous and harmful. Others are painted as being beneficial. This presents a quandary for students to explore: Are bloody suckers friend or foe? Applying a problem-based approach, students use what they learn from the program and Web-based research to explore this question and to stage a trial: Their teacher has been accused of being a bloody sucker, and it's the students' job to play the roles of prosecutor, defense, expert witnesses, and jurors. After the trial, students explain why they agree or disagree with the final verdict and the points raised by the prosecution and defense in a one to two page paper.

OVERVIEW

Learning Objectives

Students will be able to:
  • Identify the characteristics of blood sucking parasites

  • Demonstrate an understanding of ecosystem structure

  • Organize information and present it by using persuasive arguments

  • Speak effectively in a public setting

  • Demonstrate the rules and methods of formal debating

Standards

Life Sciences

Standard 6, Level III, Benchmark 1
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=2&StandardID=6
Knows that all individuals of a species that exist together at a given place and time make up a population, and all populations living together and the physical factors with which they interact compose an ecosystem

Standard 6, Level III, Benchmark 3
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=2&StandardID=6
Knows ways in which organisms interact and depend on one another through food chains and food webs in an ecosystem (e.g., producer/consumer, predator/prey, parasite/host, relationships that are mutually beneficial or competitive)


Writing

Standard 1, Level II, Benchmark 7
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=7&StandardID=1
Writes expository compositions (e.g., identifies and stays on the topic; develops the topic with simple facts, details, examples, and explanations; excludes extraneous and inappropriate information; uses structures such as cause-and-effect, chronology, similarities and differences; uses several sources of information; provides a concluding statement)

Standard 4, Level II, Benchmark 4
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=7&StandardID=4
Uses electronic media to gather information (e.g., databases, Internet, CD-ROM, television shows, cassette recordings, videos, pull-down menus, word searches)


Listening and Speaking

Standard 8: Level II, Level III
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=7&StandardID=8
Uses listening and speaking strategies for different purposes


Technology

Standard 1, Level II, Benchmark 4
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=19&StandardID=1
Knows basic facts about networked computers (e.g., computers can connect to each other via modem and telephone line, or through local network systems, or Internet and intranet)

Standard I, Level III, Benchmark 3
http://www.mcrel.org/compendium/Benchmark.asp?SubjectID=19&StandardID=1
Connects via modem to other computer users via the Internet, an online service, or bulletin board system






PROCEDURES FOR TEACHERS

Prep

Computer Resources
  • Modem: 56.6 Kbps or faster

  • Browser: Netscape Navigator 4.0 or above or Internet Explorer 4.0 or above

  • Macintosh computer: System 8.1 or above and at least 32 MB of RAM

  • Personal computer: (Pentium II 350 MHz or Celeron 600 MHz) running Windows 95 or higher and at least 32 MB of RAM

  • Software: Any presentation software such as PowerPoint or Hyperstudio (optional)

Specific Software Needed

  • No special software needed

Bookmarked Sites

Assassin Bug

Animals of the Rainforest
http://www.animalsoftherainforest.org/assassinbug.htm
The Animals of the Rainforest site features photos of assassin bugs.

Enchanted Learning
http://www.enchantedlearning.com/subjects/insects/assassinbug/Assassincolor.shtml
The Enchanted Learning site offers a diagram of and information about assassin bugs.

Bugbios
http://www.insects.org/entophiles/hemiptera/hemi_009.html
This site contains descriptive information about assassin bugs.

Texas Cooperative Extension
http://insects.tamu.edu/fieldguide/aimg51.html
The Texas Cooperative Extension site presents information about the beneficial aspects of assassin bugs.

kaweahoaks.com
http://kaweahoaks.com/html/assissin_bug.html
This site contains pictures and basic information about assassin bugs.

Vampire Bats

The Wild Ones
http://www.thewildones.org/Animals/vampire.html
Students can use this site to obtain information about the range and behavior of vampire bats.

Organization for Bat Conservation
http://www.batconservation.org/content/meetourbats/vampire.htm
This informative site features a kids page devoted to information about vampire bats.

Bat Conservation International
http://www.batcon.org/
This organization teaches people to understand and value bats as essential allies through education.

Leeches

Alien Earth
http://www.alienexplorer.com/ecology/p32.html
The Alien Earth site features useful information about the range and behavior of leeches.

Australian Museum
http://www.austmus.gov.au/factsheets/leeches.htm
The Web site of the Australian Museum contains a fact sheet with descriptions and detailed information about all aspects of leeches.

Action for Biology in Education
http://www.gondar.co.uk/abe/leeches.html
Students may use this site to learn about the classification, habitat, movement, feeding, and medical uses of leeches.

Mosquitoes

How Mosquitoes Work
http://www.howstuffworks.com/mosquito.htm
This site presents useful information on mosquitoes, including facts about their life cycle and breeding, mosquito bites, diseases, protection and control, and much more.

New Jersey Mosquito Homepage
http://www-rci.rutgers.edu/~insects/mosbiol.htm
The New Jersey Mosquito Web site offers diagrams and information about the structure and behavior of mosquitoes.

Aedes aegypti, the Yellow Fever Mosquito
http://klab.agsci.colostate.edu/aegypti/aegypti.html
This site features pictures and descriptions of the behavior and life cycle of this species of mosquito.

Everglades National Park
http://www.nps.gov/ever/eco/skeeter.htm
The Everglades National Park Web site discusses some of the beneficial aspects of mosquitoes.

Arizona University
http://insected.arizona.edu/skeeterinfo.htm
This Web site also presents the beneficial aspects of mosquitoes.

Trials

The Department of Justice For Kids & Youth
http://www.usdoj.gov/kidspage/
The Department of Justice's site for youth contains useful information about courts and trials; it also has a glossary of legal terms.

Hawaii Friends of Civic and Law-Related Education
http://www.hawaiifriends.org/mtstrat.html
This site features very useful strategies for staging mock trials, with guidelines for both teachers and students.

Materials

Students will need the following supplies:

  • Computers with Internet access
  • Pens, pencils, and other writing tools
  • Graphic organizers for collecting and organizing research
  • Index cards

Teachers will need the following:

  • Television and VCR
  • The video of the episode BLOODY SUCKERS from Thirteen's series NATURE. [It is essential for the teacher to preview this entire video. Some aspects of it may not be suitable for younger children as the pictures and descriptions can be quite graphic.]

The NATURE episode BLOODY SUCKERS has segments discussing several different examples of blood-consuming creatures: mosquitoes, leeches, vampire bats, and chipo bugs (also known as assassin bugs). [N.B. The NATURE episode discusses several other examples of bloody suckers, but the ones mentioned here have the most available information. After viewing the entire episode, you may decide to add or delete examples according to the abilities and interests of the class.] Although the video paints these creatures in a menacing light, we all know that every organism plays a positive role in the ecosystem. The first part of this unit will be to find out both the positive and negative aspects of the four bloody suckers mentioned above.

Before the first learning activity, segment out the portions of the video listed below by time signature (verbal cues are also provided) and put them on separate videos for the group-work that will take place in the next class period. As an alternative, you can stagger the groups' viewing of the video.

 Time Code  Example  Dialogue
 0130 - 0630  mosquitoes  "Some of the smallest blood-suckers are found just about everywhere..."
 1607 - 2206  chipo bugs (assassin bugs)  "Just a few hours' drive away, I'm chasing another six-legged blood-sucker..."
 2213 - 2814  leeches  "It's not the first time blood-suckers have proved useful allies to medicine."
 3502 - 5145  vampire bats  "From a new vampire to a classic one, straight from the horror movies -- not in Transylvania, but at a cattle ranch in Venezuela."

Steps

Introductory Activity

1. Cue the video BLOODY SUCKERS to the very beginning of the episode, where the lens of an old-fashioned movie projector is shown. Play the video to the point where the narrator's arm is shown ready to get some injections and stop the video at this point.

2. Ask the class if they've ever seen a vampire movie. Elicit responses from them about the movies they've seen and how vampires are depicted. Ask the class if they think that vampires really exist. Allow them to state their answers. Suggest to the class that some of the pictures in the introductory segment of the NATURE episode may give them a clue as to whether or not vampires do exist. Ask the class what they think vampires eat. Ask the class if vampires are necessarily bad simply because they eat blood. Tell the class that over the next two weeks they will be learning about real live vampires and that they will discover the answer to this question.


Learning Activities

Activity 1: (The Problem Part I)


1. Divide the class into four groups. Assign each group one of the organisms listed above (mosquitoes, chipo bugs, leeches, and vampire bats) and distribute the Student Organizer Bloody Sucker Web Sites. (Alternatively, you may wish to group students by having them draw the names of the organisms at random.) Using the video segment of NATURE related to their creature and the suggested Web sites in this lesson, each group must learn as much about their critter as they can. Each group's task will be to make a poster showing the creature. This poster must include the following:

  • at least one picture or drawing of the animal
  • a map of the world with the organism's range shaded in
  • a short essay of two or three paragraphs on the dangers posed by this organism
  • a short essay of two or three paragraphs on the benefits of this organism.

2. Once the groups have completed their posters, each group in turn presents their organism to the rest of the class.

3. Tell the class that they will now decide which organism is the worst. Tell them that the teacher will "become" that organism and be put on trial. Tell them that, in the end, the teacher will be found either guilty of being a bad bloody sucker or that this bloody sucker is, in fact, a good guy.

4. After all presentations have been completed, and the students have had a chance to take a closer look at the posters, the class will vote on which organism the teacher will become for the purposes of the trial. While looking at the posters, each student should fill out a Bloody Sucker Characteristics Organizer for each organism. They'll need this information for later use. Groups may not vote for their own organism.

Activity 2: (The Problem Part II)

1. Students receive a summons to appear in court via mail or email. The summons states that the teacher has been arrested and accused of being a bloody sucker. Students are appointed to be members of the prosecution or defense teams. One student is appointed judge (if possible, the principal or assistant principal may serve as the judge). Several witnesses must be appointed as well. They are: (1) an expert in bloody sucker characteristics, (2) an expert in bloody sucker diseases, (3) an expert in bloody sucker use in medical research, (4) a housewife or househusband who has had some sort of positive experience with bloody suckers, and (5) a housewife or househusband who has had some sort of negative experience with bloody suckers. The rest of the students are designated as jurors.

2. Research and Preparation

The class will have two weeks to research their information and to organize it in a presentable way. Whether assigned to be a prosecutor, a defense lawyer, a witness, or a juror, presentations may include any of the following elements: video clips from the NATURE episode, a Power Point presentation, posters, photographs, evidence in print, Internet sites, and/or speeches. (Note to Teacher: Elicit from the class what they know about courtroom procedures. If you think it would be helpful, suggest that students look at The Department of Justice for Kids & Youth site at http://www.usdoj.gov/kidspage/. They may also visit the Hawaii Friends for Civil and Law-Related Education at http://www.hawaiifriends.org/mtstrat.html for information on staging a mock trial.)

  • Members of the prosecuting team must develop their case. They must find characteristics of this bloody sucker and convince the jury that the teacher is harmful and needs to be put away.
  • Members of the defense team must also develop their case. They must also develop the case that this bloody sucker is beneficial to the ecosystem.
  • The members of the jury must familiarize themselves with the characteristics of the designated bloody sucker. They must also do research to find out why this bloody sucker is both harmful and helpful to the ecosystem. During the trial, members of the jury will be able to ask questions of witnesses after the attorneys have finished their examination.
  • Witnesses must become "expert" in their particular role. When on the stand, witnesses must tell the truth and only present information they know. They may not make anything up.

Activity 3: (The Trial)

1. On the first day of the trial, the judge is asked to read the indictment out loud to the class. It reads:

"TEACHER'S NAME has been identified as a bloody sucker. Enough evidence exists to bind him/her over for trial. It will be the prosecution's charge to present evidence that the teacher is a menace to the ecosystem. It is the job of the defense team to prove that the teacher is very beneficial to the ecosystem."
2. The judge calls the room to order. The judge reads the charges against the teacher, and then tells the prosecution to make an opening statement. The prosecution has two minutes to give an overview of their case. The judge then tells the defense to make its opening statement. They have two minutes to give an overview of their case.

3. The judge then tells the prosecution to call its first witness. Witnesses are examined first by the prosecution and then by the defense. Individual jurors may then ask no more than one question each. The judge must keep careful time, and no witness may be on the stand for more than five minutes total. Witnesses are called in turn by the prosecution until they have no more. The judge then tells the defense to call its first witness. The trial proceeds as above until the defense is finished.

4. The judge then asks the defense to make a one-minute closing statement. The judge calls on the prosecution to do the same. Jury deliberations then begin. Deliberations will be held in open court. Only the jurors may speak, and no more questions may be asked of any witness or of any of the lawyers. After fifteen minutes, the jurors vote in secret ballot on the guilt or innocence of the teacher.

Culminating Activity/Assessment:

Each student will hand in a one to two page paper. For the different roles, the requirements for the paper are as follows:

1. Prosecution and Defense: The losing side must prepare an appeal stating why the verdict was wrong. The winning side must prepare an answer to the appeal explaining why the verdict was correct.

2. Witnesses: Each witness must comment on the testimony of the other witnesses stating why they think the other witnesses are either wrong or right.

3. Jurors: Each juror must tell how he/she voted and why.

4. Judge: The judge must prepare a summary of the trial stating the main points raised by each side.

Extension Activities

1. Mark Ferns is the narrator and producer of this NATURE episode. Have the students compile a list of comments and questions concerning what they've learned about bloody suckers. One student or the teacher could email these to Mark: mferns@fencepost.com.

2. BLOODY SUCKERS touches upon the spread of infectious diseases, a serious global problem. Assign students a specific infectious disease to research and report on. Diseases such as botulism, West Nile virus, cholera, dengue fever, diphtheria, dysentery, ebola, Lassa fever, leprosy, Lyme disease, necrotizing faciitis, pneumonia, and Rocky Mountain spotted fever are all interesting diseases. Information about them can be found at The Centers for Disease Control Web site (http://www.cdc.gov). The search engine Yahoo (http://www.yahoo.com) is also a good resource; students can visit the "Diseases" area of the Yahoo "Health" site. Questions to be researched include:
  • What causes each disease?
  • Where is each disease a problem?
  • What are the symptoms of the disease?
  • How is the disease treated?


    ORGANIZERS FOR STUDENTS

    The following links will open a new window. Each new window will contain a Student Organizer or Activity sheet for you to print out. Close the new window to return to this page.

    Bloody Sucker Web Sites   |  Bloody Sucker Characteristics

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