You are an ecologist and decide to recreate this study on freshwater snails in minnesota. how do you replicate the presence of the predator? you are an ecologist and decide to recreate this study on freshwater snails in minnesota. how do you replicate the presence of the predator? you use crushed shells of a predatory snail species mixed with crushed shells of a non-predatory snail species. you use crushed shells of randomly chosen snail species. you use crushed shells of a predatory snail species. you use crushed shells of the same snail species you are studying.