Overeating Rat

Question
I started with one rat and fed him periodically, so he is not used to having food at all times.  I have recently introduced a baby rat with my young adult, and I have attempted free feeding so that they both get their fair share.  The older rat won't stop eating and has gorged himself to the point where is stomach is very firm and protrudes.  I am afraid that he will get ill.  I am unsure of how feeding should go.  Would it be best to free feed and keep food in the bowl at all times or feed them periodically?  Should I let the older rat gorge until he understands that food will always be available?
p.s. The younger rat adapted to free feeding very well, and does not overeat.

Answer
Never feed rats at certain times. Always allow them access to their food at all times. Rats do not overeat unless they are not getting enough food. This is one reason rats are programmed to hoard food. They eat till full and when full they will hoard food for later especially if they do not get enough.  He wont get sick. He must be hungry or he wouldnt be eating. Rats are not programmed to eat till they are sick. They cant survive in the wild if they are too full or this means death by being caught by a predator because being overly stuffed will slow them down.  You can read more about proper diet here:

http://www.freewebs.com/crittercity/ratsandahealthydiet.htm

My advice is to simply keep their food bowl full at all times. THe older rat will slow down once he is full. The reason he seems to be eating too much is because of his poor feeding habits of being on a scheduled feeding.