ghost shrimp and serpae tetras

Ahh my favorite fish, serpae tetras are great and beautiful. In my tank they seem awfully timid when I'm near the tank. When I go out of "eyeshot" it's a whole other story. They stalk the other fish, following close behind them, then poke or nip here and there - then dash off to their batcave behind my plants. Jerks. But still...my favorite.