I've got mine in a 10 gal with no fish and they are very active in it. I think the ones you usually hear about hiding are the ones with fish in the tank. Kinda like we'd do with a tiger in the room lol
They are good fun to watch if you have a bunch of them. I got 35 a while back, may have more than that now. I suggest hornwort or java moss in the tank for them however. Esp if you get breedin shrimp. They love to climb and pick at things, I always worry they're filling up on my plastic plants haha j/k.
Plus if you get the breeding kind, you'll always have cleaners for your other tanks (that, or treats for the fish in them).
Totally agree with you Rich, I have mine in a 10g too. Well, they're not alone... in fact, it's my invert tank ^_^... I had initially 35 but now, might be more and I still have 3-5 berried females (YaY!). Btw, does somebody know the time needed to a RCS for her eggs to hatch ?...