They often take refuge in the deepest part of the stream were the water is warmest. They move to the edges of the stream or pond and bury themselves in mud or leaves. There they wait until they can successfully swim again. Bullhead catfish can often become completely frozen during the winter, thaw in spring, and live without harm. Fish are not the only creatures living in the streams during the winter.
Insects also have adaptations to survive the winter.
Many invertebrates burrow in the mud or leaves for the winter. Spending their time as eggs, larvae, pupae, or adults, insects often secrete a fluid that is similar to antifreeze in order to withstand the cold. Huddled masses of water boatmen and backswimmers can sometimes be seen in small air pockets under the ice. Dragonflies and damselflies perform a similar task, but in the larval stage. Aquatic sowbugs are also active.