New BRB litter 101...
I know this comes up from time to time and last night I offered food to a large litter (28) of 5 day old full term hatchlings and had 100% success rate. Here's what I do to get my babies started out in life ...
General rules of thumb:
1) I only offer food weekly. If they don't eat, they wait a week to have food offered again. They will not starve in a few weeks or even in worse case a few months.
2) Hatchling BRB's feed best on hopper mice.
3) Of course proper temps, humidity and clean environment are a prerequisite!!
I classify the maturity of each litter into one of three categories:
1) Full term - no egg yolk to be found, babies exit from the egg sacks within a couple hours of birth. Many leave right away.
2) Short term - A little yolk on some of the babies. Nothing big and they still leave the sacks early on but not as quickly as full term babies.
3) Premature - Obvious yolk sacks. Some will stay in the egg sack for hours and hours, even days. Some preemies will require additional care to ensure the yolk does not harden in their belly.
Care for the different maturity level litters is similar but there are some key differences.
Full term, I pull babies as they clear the egg sacks and place them in a communal sweater box tub with damp paper towels to house ten(ish) babies for an hour or two to allow them to clean themselves off by slithering around in the communal tub. Ten seems to work well for me, not so few as it takes many tubs and not so many that it's hard to wrangle them all when the lid is open. Once cleaned up somewhat, Each baby is weighed then placed in a individual shoe box tub with very damp paper towels and a water bowl. Full term litters typically eat whenever offered food and shed in about 9 to 12 days.
Short term litters skip the communal tub and go straight to individual tubs. These litters will likely take a few days longer to shed and quite often are not the best eaters pre-shed. Once they do shed they do typically eat just like a full term baby
Preemie litters, if possible are left right where they are until babies are cruising out of the sacks, then very carefully transferred to individual tubs. Great care is taken to ensure the yolk and umbilical are not damaged in the process. One day later if the yolk has not been absorbed, I make a judgment call to decide whether or not to remove the yolk. Mostly I remove it unless the baby is doing a good job absorbing and not much of it is left. These babies typically take noticeably longer to shed, some take a long time, even a month. They are not good eaters to start with but with patience and proper care can grow into perfectly healthy specimens.
Yolk removal - Yup, not fun at all but sometimes is necessary to help the baby survive. If it hardens and is pulled inside the belly, I've read the baby is not likely to survive. To remove the yolk, first do a pinch test, with your thumb and forefinger, pinch the umbilical near the yolk. The intent is to squeeze back all fluids, yolk and blood so nothing is left but the umbilical itself. When you let go does anything flow back in? If yes, the umbilical will need to be tied off prior to removing the yolk. If not (be 100% certain) then tying off is not required. Tie off the umbilical with thread or non flavored dental floss near the yolk. Once tied, cut off the yolk just past your thread/floss. In a day or two you will need to do this again with the string, pinch test again and when no fluids come back in, cut off a little more umbilical including the thread/floss. Do not allow the thread/floss to be pulled inside the body cavity with the umbilical.
First feeding - I don't rush things, I feed all my babies on the same day, already started and newborns ones alike. The first food I offer is a LIVE small hopper mouse. IMO the babies do best when their natural hunting instincts kick in. I feed in the evening as that seems to work best for me. I remove the water bowl and toss in the live food and close the drawer. Repeat for all the newborn babies. Then walk away and leave the room dark. I come back in a half hour or so and typically most or all of the hoppers are magically gone. 
Individual record cards are very helpful for tracking feeding etc on individuals.
For subsequent weekly feedings I work them down the following path. If they take the next step great, if not I back up to prior step.
1) Live hopper mouse (first feeding)
2) Fresh killed (F/K) hopper mouse - second feeding
3) Warmed up frozen thawed (F/T) hopper mouse - after several feedings with F/K
I also will mix in live pinky rats depending on what I have available. Overall for the large group I go in somewhat reverse order since some will refuse items further down the list.
First, I offer them pinky rats until all the pinky rats are eaten.
Second I offer those that have not eaten yet a F/T hopper mice until all those are eaten.
Third I offer the new hatchlings live hopper mice.
Lastly I offer the remainder of the babies a F/K hopper mouse. One at a time saving one I know will eat for last. Any that refuse the F/K are offered a live one.
Typical progression is one or two live, a few-ish F/K then eat anything offered.
Non live food is introduced by opening the drawer and dangling it by the tail near the head but not touching. If possible, I bring it in from the other side of the water bowl so their ambush instincts kick in. If they appear attentive but not striking I slowly retract, if they follow, the strike will usually come soon. Once the baby strikes, I wiggle the feeder a little to get full on constriction and then let go. Sometimes they are under the paper towel and I actually lift the baby out from under the paper towel and set on top so I it's easier to verify later that the baby actually ate the feeder. If my dangling and slow movements do not work, I let the feeder touch the baby to get it's attention. Lastly, if still not eating I will leave the dead prey in the tub, closed for a half hour or so while working on something else. I post-it note the tub to know which one(s) to check back on.
Note: ALL tubs are checked to verify actual consumption of the feeder!! I have left F/T overnight on occasion but always checked before the food has a chance to go rancid.
With dozens and dozens of babies each year, I do find a very small few that won't eat on their own. I continue to offer food weekly for about one to two months. If not eating by then I try "assist feeding" a F/K fuzzy. To assist feed you simply open the snakes mouth (with the nose of the feeder) and insert the head of the feeder and see if the snake then swallows. Some will but more likely will spit it out then comes the full on force feeding where you stuff the food item far enough down so the snake will swallow it.
If assist fed, then offer live the following week and assist if necessary.
If force fed, skip the next meal and then two weeks offer live / force feed again.
After a few rounds the snake usually gets the idea and eats on it's own. IN all my babies I've only had one so far that never got the idea. That one went to a friend and is still being force fed to this date.
Will be working on turning this post into a care sheet for my website, eventually will have pics scattered through it showing various aspects. Any and all input welcome!!!!
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Thanks,
Dave Colling
www.rainbows-r-us-reptiles.com
0.1 Wife (WC and still very fiesty)
0.2 kids (CBB, a big part of our selective breeding program)
LOL, to many snakes to list, last count (05/26/2009):
36.51 BRB
29.42 BCI
And those are only the breeders 
lots.lots.lots feeder mice and rats 
