To begin we will explain the operation and the work of this experiment.
We could see that in the first source there was no insect and it was very dirty (a lot of waste and very muddy water) because there is a lot of passage (cars, station, store, waste).
Regarding the second source, there is no passage because it is in the middle of the forest. The water is very clear and there are a lot of insects. Under the rocks and pebbles we find dozens of insects at once.
Do not take your waste in nature !