I bought 4 Amazon PUFFER-FISH, all low down at the bottom like dead. After a few hours they moved around a bit and then lied down. I have snails in the tank and some guppies. They are not eating anything .I tried frozen tubiflex worms, they didn't eat them. Also they are very shy. When They see me coming they all play Dead. What should i do. How so i start to comfort them.