I have a new aquarium set up thats been running for over a week. I have 10 Neon Tetras in it. The tank is right next to my bed. Over the past 3 days when ever I sit on my bed one Tetra comes over and if any others try to come to my side of the tank it chases them away. If im not near the tank they all swim together, its just when im near it. Is this normal ?