I have Tigers and Cherries. In a predator-free tank like mine, ther are active and "cruzing around" all the time. Extremely prolific in my tank. When I put my hand in the tank they're all over it :-) Very cool.
These shrimp are the best. They are pretty hardy, they are active, they all look a little differant. Mine too jump on my hand and clean it. Tiger shrimp are natural beauties. I have RCS and crs the tigers are my favorite.