The Roach Guy. These hydrated blobs can be used as a bound water source so cockroaches can get a slurp of water. If it weren't bound in a gel, this whole setup would quickly turn into a blob of mold.
I use them for visible gardens. In this application launched last night, I filled the see through plastic frame (thrift store find) with hydrated gel half way, then placed a few seeds and filled it in with more hydrogel. I used basil seeds and ... some other kind of seed, I forgot. It's a fun thing to look at during breakfast. Grass seeds tend to take about 7-10 days to initiate a sprout and then grow pretty quickly. Weekly watering is about all that's needed. The observations every morning make it fun. If you're a local and want some of the gel to play with, it's not toxic and I have some extra, just let me know and I'll get you some.