Zombie Ants Research Packet
SIOP Science • Levels 1 & 2 Bilingual & Visual Scaffolded Edition
Name:
Date:
🎯 Content: Learn how a fungus and chemical make ants act like zombies.
💬 Language: Use pictures and sentence frames to explain scientific findings.
Real Science Case Study
Which Chemical Makes Ants Walk Like Zombies?
Adapted from research by William C. Beckerson, Courtney Krider, Umar A. Mohammad, & Charissa de Bekker
Insects
🧟
SIOP Vocabulary Anchor: What is a "Zombie Ant"?
Key Concept
In scary movies, a zombie is a monster that cannot think. In real nature, a "zombie ant" is an ant whose brain is hijacked (controlled) by a parasite!
• Normal ant: Healthy, works with friends, walks straight.
• Zombie ant: Sick, staggers (stumbles clumsily), leaves the nest, and cannot control its legs.
Fungus Hijacks the Brain! Staggering Legs! Brain Hijacked by Fungus
1 The Mystery Fungus: Ophiocordyceps
The fungus is named Ophiocordyceps (say: off-ee-o-kor-dee-seps). When it infects an ant:
- • The ant stops working and leaves its underground nest.
- • It walks like a dizzy zombie and climbs high up a plant.
- • It bites the leaf in a death grip and dies!
The Science Detective Question: The fungus makes a poison called aflatrem. Does aflatrem make the ants stagger and lose control?
FIELD PHOTO • NATURE STUDY Figure A
Spores floating Fungus stalk Death Grip (Jaws)
Figure A: Real ant infected by Ophiocordyceps. The fungus sprouts a stalk out of the ant's head to shoot spores into the wind.
Step-by-Step: How the Fungus Takes Over
1
Spore Lands
Fungus enters the ant's body shell.
2
Zombie Walk
Toxin makes the ant walk clumsy & dizzy.
3
Death Grip
Ant locks jaws on a high leaf and dies.
4
Spores Spread
Wind blows spores to infect new ants!
Zombie Ants Research Packet • Page 1 of 4 Turn to Page 2 for the Scientific Experiment →
Experimental Design • Step-by-Step
Methods: How Did Scientists Test the Ants?
LAB PHOTO • FIGURE 1 Beckerson Lab
Glass Micro-Needle Ant Thorax
Figure 1: Microinjection. Scientists used a tiny glass needle under a microscope to inject precise doses of aflatrem into ants.
Step 1: Collecting Healthy Ants
Scientists went to an arboretum (a protected garden where trees and plants are grown for science study).
They caught 3 healthy colonies of Florida carpenter ants (Camponotus floridanus). Each colony had 100 to 200 ants.
All ants were healthy and normal before the experiment.
Key Science Words: Solutes, Osmolarity & PBS Saline
Cell Health
Aflatrem cannot dissolve in plain water. It must dissolve in acetone (a clear solvent) and mix with PBS (phosphate-buffered saline). Why? Living cells have dissolved particles called solutes. The solute balance is called osmolarity:
😖
Too Much Salt
Water leaves cell; cell shrivels up!
😊
Balanced PBS Saline
Perfect osmolarity; cell stays healthy!
💥
Too Little Salt
Water floods inside; cell explodes!
C Why Did Scientists Need Two Control Groups?
A control group shows normal baseline behavior to compare against. The researchers needed two control groups:
Control 1: PBS Saline Only
Shows normal ant walking after receiving a harmless salt liquid injection.
Control 2: Acetone + PBS
Proves that the acetone solvent alone does NOT make ants stumble or stagger!
4 Test Groups: Injected with 10 ng, 50 ng, 100 ng, and 500 ng of aflatrem. Tracked for 30 min
Zombie Ants Research Packet • Page 2 of 4 Turn to Page 3 for Results & Behavior Pie Charts →
Results • Data Visualized
Results: What Happened to the Ants?
Figure 2 from Original Research
Percentage of Behaviors Observed with Increasing Aflatrem Doses
Tracking time: 30 minutes
Control
PBS + Acetone
0% Stagger
10 ng Dose
Tiny dose
8% Stagger
50 ng Dose
Low dose
18% Stagger
100 ng Dose
Medium dose
30% Stagger
500 ng Dose
High dose
48% Zombie!
😵 Staggering 🚶 Walking 🧗 Climbing 🧼 Grooming 😴 Resting
→ More Chemical = More Staggering!
Inside the Ant Head: What Happened to Genes & RNA?
Cellular Discoveries
Scientists read the RNA (ribonucleic acid) using a lab technique called sequencing. They discovered:
261
Genes Altered
Turned ON or OFF by aflatrem.
Muscle & Brain
Body Pathways
Controls movement signals to legs.
113
Fungus Matches
Exact same genes as real infection!
Discussion: Why Does the Fungus Force the Ant to Climb High?
The fungus makes the ant stagger and freeze in place high up in the forest canopy. Why? When the ant dies at the top of a plant, the fungus can sprout its stalk into the air. Wind blows the spores across long distances, showering spores down to infect the entire ant colony!
Zombie Ants Research Packet • Page 3 of 4 Turn to Page 4 for Glossary & Questions →
Reference & Assessment
Glossary of Key Terms & Check Your Understanding
SIOP Scaffolded Edition • Page 4 of 4
Glossary of 12 Key Terms (Word Bank)
Review before writing answers
1. Acetone (AS-uh-tohn)
Clear solvent liquid used to dissolve chemicals.
2. Aflatrem (AF-luh-trem)
Toxic poison that makes animals stagger & shake.
3. Arboretum (ar-buh-REE-tum)
Garden where trees and plants are grown for study.
4. Control group (baseline)
Test group showing normal behavior to compare.
5. Genes (JEENZ)
Cell instructions that tell the body how to function.
6. Pathway (PATH-way)
Body route that carries signals between cells.
7. PBS (saline buffer)
Safe salt water matching natural insect blood.
8. Ophiocordyceps (fungus)
Parasitic fungus that turns ants into "zombies."
9. Osmolarity (salt ratio)
Balance of dissolved solutes to liquid in a cell.
10. RNA (messenger)
Molecule carrying instructions from DNA to cells.
11. Sequencing (reading)
Lab test that reads the genetic letters of RNA/DNA.
12. Solute (SOL-yoot)
Solid powder (like salt) dissolved into a liquid.
Check Your Understanding (Complete the Academic Sentence Frames)
Fill in the blanks or write your own answer
1
What is the purpose of a control group? Why did we have two control groups in this experiment?
Page 2 Clue
The purpose of a control group is to show normal baseline behavior. We used two control groups to test PBS and to prove that acetone solvent did not cause the staggering.
2
Why does the Ophiocordyceps fungus make the ants climb to a high place before they die?
Pages 1 & 3 Clue
The fungus forces the ant to climb high so that the wind can blow spores far away to infect more ants down below.
3
Evaluate the significance of the genes that became more active after the ants were treated with aflatrem. Why might these changes matter?
Page 3 Clue
These gene changes matter because they control muscle contractions and brain signals. This explains why the ants stagger and walk clumsy like zombies.
4
Predict how the ant colony might react if many ants became infected with Ophiocordyceps at the same time.
Synthesis
If many ants were infected at once, the colony would collapse / lose workers because the sick ants leave the nest and die.
Zombie Ants Research Packet • Page 4 of 4 ✓ Complete & Turn In to Teacher
