I don't know how they do it, but herps will stunt themselves to the size of their container, like fish. Once a boa or other snake has "grown in" to its cage, it may slow its rate of lengthening, and the same old amount of food will just fatten it. Put that animal into a larger cage, and after a few months it will have a growth spurt, and might need the extra food again. Once a snake has grown to its housing, think about watching the boa instead of the calendar to feed it. Does it look thick? Is it turning into one of Herman's "truck tires"? If it's thin, feed it. If it's heavy, don't. I really think this is a key factor in the stories of healthy boas eating six meals a year.
I promised 2 points, so here's the second: wild game is very lean. I'm not a hunter, so I didn't know this, but a few years ago a hunter friend gave me some elk meat. He cautioned me to use lard or other fat when cooking it, or it would dry up in cooking. No kidding. I noted the point that wild game is almost fat-free, and forgot about it, until the fat boa thread appeared on the forum. I expect that wild boa food is likewise low-fat. I also suspect that lab rats are not so low-fat. I don't quite know what to do about this; I have no alternative to feeding large numbers of pet boas other than to continue feeding lab-grown food, but it may be a factor. Again, it probably pays to keep an eye on the boa.
I also call your thoughts to a final (bonus) point: I really am serious about breeding my boas when they grow up, and I took note of Herman's comic reference to overweight boas as truck tires. I also note that Gus, who has pretty good success with his boas refers to overwieght boas by another term. He calls them non-breeders.



