I'm looking for some little invertebrates to colonise a paludarium I'm building...
I'm looking for-
springtails- look like fleas.. They like moist soil, and jump like mad. They don't bite though.
freshwater sponges- related to marine sponges.. They look like brown algae, but aren't 'soft', and retain their shape. They die if exposed to air, so these would have to be put in a container underwater.

water striders/water treaders- they can bite, so be careful.
freshwater jellyfish- Yep. They can't hurt humans.
Water louse- Like pill bugs, only aquatic. Also, scary looking.
Daphnia-
white specks swimming in the water.
Hydra- Sure, why not. They look like anemones.
Freshwater Limpets
Might as well throw in a handful of detritus from the bottom too. I can plant my plants in it.