Looking at a stream, what do you see? Running water, rocks, sand. Maybe plants, maybe fish. But did you know that the bottom of the stream is teeming with life as well? Amongst the rocks, macroinvertebrates are clinging-on, crawling around, catching food that comes by, or hunting their prey. This activity will help you become comfortable identifying macroinvertebrates and recognize the special adaptations each as to its aquatic habitat.

What's great is that these "critters," by their presence or absence and abundance, can actually tell us the health of a stream. Some are sensitive to stream pollution and will not be found in unhealthy streams, while others are tolerant of pollution and can live in water with poor quality. For this lesson each animal has been given 1-3 points, based on how sensitive they are to pollution. Because more sensitive macroinvertebrates indicate healthier streams, they will be given more points. Complete this activity by identifying all six animals - the stream with the most points is healthiest. Have fun!