so I've bought 2 oscar about the same size, around 4" each, one of them seems to be OK when I'm around, and begging for food all the time, but the other one, is scare of me, and doesnt seems to eat much, do you guys hv the same problem before?how to solve this?should I starve it for a while?each are in the different tank on they own, 40 galls each