As a kid, I wanted these so badly. I bugged and bugged my parents until they finally caved in. Of course, I never saw a single sea-monkey. Don't know what I did wrong, but I was devastated. Little did I know that as an adult I've hatched them by the thousands. Turns out the cute illustrated family of sea-monkeys is nothing more than hybridized Artemia (brine shrimp). The hybridization was designed for fast growth and large size, up to 3/4". The Artemia I've hatched never get much larger than a dot before they are fed to newly hatched fry. Maybe as an adult I'll step things up and give these more challenging Arsenic-Based Sea-Monkeys a try. Just can't decide if I should get the optional protective suit and face mask with respirator.