I have had a little Jack for about 6 months now. I bought it at PetCo when it was about and inch and a half or so long and now it is between 3 and 4 inches long. Anyhow, he/she was always very friendly...would swim up to the glass when you come by..eat from your hand ect.. now the past 2 days he/she has been freaking out when you walk near. He/She jets away from you and even smacked the glass a few times trying to get away. I noticed that he/she has started burrowing in the substrate and hiding. Is this normal? He is all alone..well there is one Dwarf Gourami in there with him that he doesn't mind (yet) Help!! I am worried. I just took a sample into my LFS and the perimeters are "perfect" he said. I don't get into all that with him because I don't understand that. I test once a week when I go in to buy fresh food. ~Vonna