i have a vamp. shrimp.. he lives with kribensis, south american pufferfish, glass cats, ammanos and oto cinclus. a vampire shrimp will normally find one spot to live in. for the first while.. this could take over a month before it decides to venture out. i have lots of rock in my tank with big caves, yet he picked a spot a little bigger than his body and actually lived upside down for quite some time. after his fiirst molt he started to come out more.. now that he is comfortable he comes out daily. but this took awhile. he is still very cautious to fast movement outside the tank. just give it some time as vampire shrimp take a while to become comfortable. but they arent really "afraid" of much. when i first got my oto cats.. one went directly to the shrimp and started cleaning him. the shimp did not care. just give some time and observe the tank without moving. my shrimp is smart.. his home is infront of the intake of the filter so any particles that go to the suction of the filter go through him first. they also go crazy for bloodworms. a dose of those in the tank and the shrimp looks like he needs more than the four arms he has to feed himself.