II.C.1 Part Three--Ant Communication
During this project, students will observe how ants recruit other ants to resources,
such as a dead grasshopper, or, in this case, tuna fish. Because your students may need a
lot of experience observing, you may want to give them two opportunities to do this part
of the activity. The first time, have students just observe and follow it with an informal
class discussion. The second time, students can do a more formal investigation.
Each team of 2 students needs:
- Student Data Sheet #2
- Hand lens or magnifying glass
- Small cup with bait (Tuna fish works best. A 1cm chunk, about the size of a pea, will be
- Ruler (metric)
- Digital watch or stopwatch
Teacher will need:
- A small bag to collect the empty bait cups
- Soda straws for ant experiments (to distribute to teams who may need them)
|Instructions for the teacher:
- You will need a dry, warm day (70EF or above) and approximately 20-30 minutes to
complete this activity.
- Divide the class into teams of two.
- Distribute and review Student Data Sheet #2.
- Give each team a cup of bait.
- Students will work within the area established for Part Two,
#3 of this activity. Instruct the teams to set up their bait a short distance (0.5-1.0
meter) from an ant nest. Students should watch how the ants aggregate around a food source
and transport it back to the nest. (Ants lay down scent trails between the food and the
nest entrance to help other ants find the food. Scent trails are deposited by a gland at
the tip of the abdomen, so an ant returning from a bait can often be seen "dragging
its tail." The scent trails are picked up by the antennae.)
- The students will observe what happens and complete Student
Data Sheet #2, questions #1-7.
- Teams should then plan their own experiments as instructed on the data sheet. Students
should not kill ants during the procedure. The experiments can be very simple, such as
drawing a finger across the trail in the sand. All experiments should:
- Have a hypothesis
- Record the experimental procedure
- Report on the experiment
Some simple experiments with ant trails include:
When all teams have completed the data sheets, return to the classroom for a quick
review. The principle themes that should come out of this discussion are:
- interrupting the trail in a variety of ways
- removing the bait
- changing the bait
- moving the bait to another place
- altering the scent trail by getting the ants to walk across a piece of paper or a bit of
leaf, then turning it around, etc.
- The ants that return to the nest while laying down the trail return more or less
directly, they do not wander around like an ant that is out looking for food.
- The scent trail is a simple and versatile communication system.
- Working as a team, the ants are much more efficient.
The experimental method approach utilized by students in #7 on the data sheet, is still widely used in science, especially
in the early stages of a research program. To be considered scientifically valid, however,
the method must be repeated over and over again. Even if the experiment is only completed
a few times, it can be useful as an indicator. The important point for the students to
learn (aside from interesting ant behavior) is that it is necessary to carefully describe
what was done, so the experiment could easily be repeated.