Freshwater crayfish are small, aquatic crustaceans found in rivers, lakes, and streams. They have a hard exoskeleton, two large pincers, and a segmented body. These creatures play an important role in their ecosystems by helping to recycle nutrients and serving as food for various animals, including fish and birds. There are over 500 species of freshwater crayfish worldwide, with the highest diversity found in North America. They prefer habitats with plenty of hiding spots, such as rocks and vegetation. Freshwater crayfish are also popular in aquaculture and are often harvested for food.