one of my emperors hasn't moved in over a day and a half he is just sitting in a corner of the tank and yesterday its tail was layin flat by its side like its was sleeping but out in the open i touched gently and he jumped back ready to sting he is smaller then the other two i have (think there female) is it possible hes ready to moult , but stinger looks like a light brown already.

Post us a pic.

Not moving is absolutely normal; not moving with the tail out flat usually means death is near. However, with the reaction you described, you may have just caught it poopin'.