well, if puffers are nocturnal then i think it would probably come out if you turned off the lights for a little wile. It sounds like its just scared of all the people and lights and sounds around its new home. Try being quiet for a little bit and see if it comes out, and it would help if you turned off the lights too. That sort of thing seems to go with most fish. My firefish hides whenever someone walks pat the tank, but comes out when you sit there for a little bit and just watch the tank.