When the time comes a salmon will begin to return to the stream from which it was born. During this stage the salmon will stop eating a begin to live off of it's fat reserves. They will swim all the way up stream and back to the same river they were born. After they return the female salmon dig nests in the gravel that are called redds, they then lay thousands of eggs. After the eggs are laid male salmon spread sperm or milt onto the eggs to fertilize them. Then the female salmon goes back and covers her nest. Of all the eggs laid by the female salmon only 1-10 will live to adulthood. After spawning the salmon then dies to make way for a new generation.