I'm assuming your tank is new? For the first week that they were in my aquarium, all of my fish hid from me. Just try to imagine what it must be like to get netted, moved to a completely new place with new surroundings, and then have a creature 1000 times your size stare at you. How do you know you aren't lunch?
Give them some time. Eventually they'll recognize you as the 'hand that feeds them.' After a while when they see you, they'll all scream up to the front of the glass to beg you for food.
After having had my aquariums for 3 months, I actually kind of enjoy watching them when they haven't seen me yet. It gives me an idea of how they really are. The second they see me though, they all come to the front of the glass, excited to see me.......OK, they really just want food. hehe!
38 Gallon (Freshwater): 1 Green Swordtail, 3 Yo-Yo Loaches, 1 Clown Pleco, 1 Blue Gourami, 4 Otocinclus, 7 Cherry Barbs.
46 Gallon (Saltwater): 60 pounds Lalo Live Rock, 60 pounds aragonite sand, 1 Coral Beauty Angelfish, 1 Peppermint Shrimp, 1 Mushroom Coral, 1 Emerald Crab, various snails and hermit crabs.
10 Gallon (Saltwater quarantine):