Peal a hard boiled egg and mash it up into small bits.  Next scoop up 1/2 cup of uncooked old fashion rolled oat meal.  Give these two treats to your biddies on a clean piece of cardboard.  If they wont leave the nest for hard boiled egg, I am afraid that your chicks are dead.  
		 
		
	 
Well, I must have some zombies then. 

 Boiled up some quail eggs as they are faster and more "chick sized" and scrambled them and added a bit of oats... Well, They poked their heads out but didn't leave. I took mama out and she food called, and they finally came running out, and mama headed to the door to lead them outside once all of it was gone... Nope, babies ran right back into the nestbox.
I agree with mama hen, "Grah"
I put a small bowl full of stones infront of the nest so mama can get some water as it is a hot day. It didn't have stones at first but after an enthusiastic chick face-planted in it and scared me half-to-death by acting like it had breathed some in, before sneezing it out and returning back to it's ordinary chirpy self. The water wasn't even that deep, it was like, ankle-high for the tiny chicks. 
	
		
	
	
		
		
			Yeah, those five-day olds ought to be hungry by now. But it's easier for the broody to teach them to eat if you sprinkle chick crumbles over the floor. I also used minced boiled egg to supplement the food during the first week.They should also be able to easily access water. Have they drunk yet?
If you do not have the chicks in a nest on the ground, it makes it nearly impossible for the hen to get them down out of it, let alone back up into it. Think about logistics. A broody nesting free range wouldn't build a nest up high. Or most wouldn't.
		
		
	 
I have the nest on the ground and they can jump in and out with ease, and they have been eating and drinking fine when they decide to leave their little den, otherwise I have to put food in for them so they don't starve. They do have a little waterer I put outside the nest before I put the bowl by it for mama, which they used when I brooded them (to ensure they were eating, drinking and pooping properly) they pop out every now and then to drink from, but always go right back into the nest.
A vid from when they were outside, I brought the box out with them for easy nest access and also for easy water access by the water bottle. Mama hen is used to me moving her nest about from when I had to clean the kitchen floor when she was brooding.