Without any details we have nothing to work with - what's the water like, including temperature. What is your stocking list? How is the tank set up?
If you have a ton of hiding places then it might be worth trying to thin them out so that it creates more competition in the tank, or add more fish if it isn't overstocked yet. Depending on what the water temperature is now you can try warming it up a bit, which can increase their activity. Perhaps you've just chosen some calmer species and adding something to stir things up might be an option.