they also can be good food for fish. I just added some two days ago, can't quite tell how many are hiding (which there are plenty of spots to hide) and how many were eaten; I'm fine with either out come. I know some are alive and found spots to hide.
Mine cost $1.50 for "a half dozen". That half dozen was really just a quick swipe with the net in the ghost shrimp tank and I received well over a dozen shrimp for the price.
-in response to your question in your sig "how do you put pictures on here" go to the member's aquariums and fish pictures forum section and there is a pinned topic