An experiment is to be conducted using an environmentally safe electronic deterrent system to study the effectiveness of deterring woodpeckers from damaging trees. The electronic system can be set to four frequencies to deter the woodpeckers. The researchers will determine the adverse reaction of the woodpeckers to the electronic deterrent by starting with trees with no holes and counting the number of holes after one week of using the deterrent. There are 48 woodpeckers available for the experiment, and the researchers will use 12 birds for each frequency of the electronic deterrent. For this experiment, identify the treatments, experimental unit, and response variable.