The organism I chose to study are ants.
Throughout the course I watched where ants were in my yard including in my garden, the part of the yard closest to the house, and the part of the yard that is behind a row of trees that was covered in weeds.
I noticed at first there were a lot of ants in the garden by some of the plants I had planted. There was also an abundance of ants in the yard by the house, despite a pool, a trampoline, and children often playing out there. As time went on, I noticed a shift in where the ants were. There are now less in the garden area and in the yard by the house. However, I noticed that there are now ants in the very back patch where there was none before.
A hypothesis I have about the change in ant location is that the effects of the round-up weed killer has decreased due to lack of use making the back half more hospitable.
One potential response variable is the abundance of ants in certain areas in the backyard (garden, main yard by the house, and the back part). A potential explanatory variable is that effects of the weed killer is wearing off. This would categorical as it will be measured by the absence and/or presence of ants.
You have your response and predictor variables a bit off, though they are close. Your response variable is the abundance of ants or presence /absence depending on how you choose to measure ant activity. Your predictor variable I think is level of development / vegetation type. I’m not sure how you will get at the effects of weed killer.