Coral shrimps (just like any other ) are very shy and retiring on th whole, they prefer to keep out the way.
Cleaner shrimps are different, they will stand boldly ona rock and advertise their presence for fish to get cleaned. Generall the cleaner shrimps and (more so) Bloodshrimps will be on show far more often if you have them in small groups of 3 or more. I have 2 cleaners and 3 Blood shrimps and they are nearly always on show.
However...
DONT try this with a coral/boxer shrimp. They dont like company and they will fi ght to the death )