Duncan won't eat

My duncan is no longer feeding when I target feed. When I first got him 2 weeks ago I fed him once a day. He ate all the time. I have tried to target feed him for 3 days now and he won't grab any of the food. I have tried with tweezers and with a turkey baster blowing the food slowly so not to spook him. But all he does is close up or retract slightly without any food. Any one know why or if he will still survive without target feeding large foods? He's been closed up for most of the day for about a week before the past 3 days.