I would gently scoop up those boy rats and smoothly pull them into my chest, making sure to support all their limbs...they learn to be more secure when being picked up and held...they hate dangling until they feel they can trust you.
I would put them on a couch, and sit or lie on it...have a pillow in the corner so they have a "safe" spot, put a small blanket over you for more "cover" and read a book, or watch TV. Do normal things, let them jump and get used to it all. With your attention on them they are more nervous, then if you ignore them and let them figure things out a bit and relax. They say that a rat can only stay truly frightened for 20 mins and after that will begin to relax. Slowly they will poke a nose out and since rats are naturally curious, will check you out from afar. You can talk to them, but don't try to touch them yet.
The braver ones will eventually come closer and if you feel they are ready, very quietly attempt a small stroke on a back, and then stop. They will realize...hmmm...that didn't kill me? Baby steps...go slow, let the rat lead you, watch body language. Bug eyes, tense posture, freezing, all are big signs or fear or nervousness...grooming is much more relaxed. You can always try baby cereal on a saucer once they are more relaxed. Then they will associate you with Out and yummy things. Btw some rats take a long time before they will take a treat from your fingers...don't use that as a barometer.
Start here, and see what happens...quiet approving voice, quiet smooth movements, watch the body language...
Good luck with your kiddo's!!
I have used this method for years but one of my greatest successes was taking in Foster Shrek last spring who was a biter. I had 2 weeks to turn him around or he was going to be pts. I did all this with him (taking him out of his cage with gloves at first), absolutely dreading the feeling of the crunch as teeth go thru to bone.
By the end of the first session I had him eating baby cereal on my stomach in a little plate.
He taught me a lot about body language.
T-man could you put up pics of your 4 boys? Sometimes I can get a feeling of body language from them.