It used to be that when I would feed my two little platies I'd turn on the light and they'd shoot to the top of the tank ready to eat. But since starting grad school I spend a lot more time at my desk which means I spend a lot more time vacently watching my fish with the tank light on. With in a couple of days all I had to do was tap my finger on the 'glass' a couple of times and they'd shoot up for food.....do fish really learn that quickly?