I may be wrong but I'm starting to think the "feed in a seperate container" is a kind of urban legend?
Literally, I have dozens of snakes. Each and every one fed in it's tub/cage. I do not have any that are overly agressive when the enclosure is opened. OF course, on dinner day, they know it and are actively looking for dinner.
IMO, it has more to do with if the only time the enclosure is opened is to feed. I open every enclosure, pull every tub daily. Yes I have some that are more agressive than others. I also have some young-uns that are likely to hiss at you. Working with them has fixed all these issues. AND, agressive behaviour is usually a SYMPTOM of something else. I have one girl that was always there ready to bite when the tub was pulled. I increased her feeding schedule a little and problem fixed. They are all individuals, she was just hungry!!! Gonna be one of the bigger girls as an adult. Can't change genetic pre-disposition!
Other urban legend is babies get stressed out in large cages. Babies get stressed out when they can't hide from predators. Appropriate hides in a large cage will work just fine!!
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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:
26.49 BRB
20.21 BCI
And those are only the breeders 
lots.lots.lots feeder mice and rats 

