I have the answer to this problem, it involved the boot of a car, a sack, a bat, and a lonely counrty lane, first you take sack from boot, then proceed to ...............
Only joking, as the lads have said, handle as often as poss, are they in the same cage, if so try two different cages, they may be competeing for food, and it sounds like they want the food from the hand, try feeding them from different cgaes and see what happenings.