Young adult lamprey emerge from the stream bed and stay in the same stream if they are a brook lamprey or migrate downstream and into the ocean if they are a Pacific lamprey. Pacific lamprey adults eventually latch on to larger fish and live parasitically on the blood and body fluids of host fish. Brook lamprey do not feed as adults, but instead only breed. After a few years at sea, Pacific lamprey migrate back up streams, no one knows if they go to their natal stream, to dig small, circular nests or “redds” to mate, lay eggs, and then die. Brook lamprey spawn in a similar manner, but in the same stream they have lived in their whole lives. Lamprey have gone extinct in many western streams due to habitat and water quality changes and there is increasing concern about their long term future in many of the streams where they still exist.