On Monday our class made eco-bottles.  It was three bottles taped together.  One bottle {bottle A}  has dirt and leaves like what we have in the forest. There are crickets and worms as animals.  Then we have bottle B, it has nothing in it.  Bottle C, it has rocks and water with some water plants. We have two fish and one snail in there as well. It represents symbiosis, a relationship where at lest one organism is benefiting. They provide nutrients for one another and the plants provide oxygen.