I raised them many years ago. I thought they were very kool.
They are basically the same thing as sea monkeys - instant minipets, as kittycat put it. The package comes with a container to place sediment and water in. I don't remember if it comes with a package of dirt, or if I got some from the yard. It also comes with a package of triop eggs. After so long, the eggs hatch, and tiny triops will burrow out from the mud.
They grow about an inch or so long, and they look just like tiny horseshoe crabs.
You should try them, they are really enjoyable, and very cute. Mine lived for several weeks, and would have probably lived longer if I hadn't of went on vacation and left them home alone.
I can't really give details about caring for them because I had them when I was 9 and I barely remember setting up their environment. I do remember that they were awesome little creatures with big appetites (package should come with food pellets for them) and they were highly active and loved digging in the mud. At times I would even pick one up out of the water for a few seconds and pet it.
I wish I could find them around here again. It's been years since I have seen them
