How long have you had it? Most of the shrimp I have had, hide for the first week or 2. While I will not say that I can find mine all the time, he is usually lurking somewhere that I can locate most of the time. Coral Banded shrimp prefer a cave or shaded overhang to hang out on. You might rearrange your rockwork to provide a ledge he can hang upsidedown on where you can see him/her.