Side Note: They are really called Wormies, I am not making it up.
The Low Down
These wormies are made out of ceramic clay like terracotta pots. When they are wet/moist they soak up the water and are dark in color. When they are dry, they are light in color. Trick is is that you have to check with wormie same as you would the soil to see if the plant needs water. I can hope that Steel will keep an eye on them for me and let me know. He was fasinated with them. The directions also mentioned that the wormies need to be soaked in water for 2 minute prior to use. I am assuming this is to wash off a type a protective film on them, although nothing was visible on the surface.
Wormies in action