Meet a Macro

We all know about the big things that rely on clean water: fish, wildlife, plants... and, of course, us! But what about the little things that rely on clean water?

Even the tiniest streams can be home to little critters called aquatic macroinvertebrates. "Aquatic" means they live in water. "Macro" means you can see them without a magnifying glass. And "invertebrate" means they don't have a backbone.

These itty-bitty animals, affectionately known as "stream bugs", are completely dependent on clean water – especially those that are pollution sensitive, or unable to survive in water contaminated with chemicals, excess salt, and other stuff that doesn't belong in waterways.

Some of these stream bugs spend their entire lives in the water. Others grow up to become animals we're more familiar with, from mysterious mayflies to delightful dragonflies.

These short videos (less than 10 minutes in total) will introduce you to the fascinating creatures that live in streams. Go ahead – Meet a Macro.

Black fly larva
Caddisfly larva


 Learn about one of our Chesapeake Monitoring Outreach Coordinator's favorite stream bugs.
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Crane flies

 Learn why you should keep a sharp eye on the larval crane fly.
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Black flies

You're likely to meet a black fly anywhere you find a stream.
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Why are these little bugs called "May" flies?
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It's a clump of dirt! It's a rock! No - it's a caddisfly!
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Did you learn to recognize these tiny friends?


Take the quiz and find out


Caddisfly larva