>>The chemical name is: sodium polyacrylate. I'm not sure if it has any toxicity when ingested ...
http://www.camd.lsu.edu/msds/s/sodium_polyacrylate.htm
http://science.howstuffworks.com/question207.htm
http://www.madsci.org/posts/archives/mar99/921040790.Ch.r.html
http://www.chemindustry.com/chemicals/search/S/sodium_polyacrylate.asp
"Google" will give you others.
I don't think that it is the best stuff to use for providing water for animals. I know that the crickets seem to do okay on it, since I've used it for them in the past; but I have some anxiety about whether or not it could irritate the bowels of their predators.
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tricia