Answer:
To test how robins capture worms, the following experiment can be designed:
Variable: the method used by the robins to capture worms
Control Group: a group of robins using their natural method to capture worms
Experimental Group: a group of robins trained to use a new method to capture worms
Experimental Design:
Obtain a group of captive robins
Provide them with a habitat that includes soil, grass, and worms for food
In the control group, allow the robins to capture worms using their natural method
In the experimental group, train the robins to capture worms using a new method, for example, by digging the soil in a particular way or by shaking the soil to make the worms come out
Observe and record the number of worms captured by each group of robins
Compare the results to determine if the new method is more or less effective than the natural method.
Diagram:
Control Group (natural method)
| |
Robins ----> Soil ----> Worms
Experimental Group (new method)
| |
Robins ----> Trained Soil ----> Worms