"I'm not sure how this "don't put a snake in a big cage or it will get scared" rumor got started. If the snake has multiple hides to crawl under/ tuck into it will be fine."

I've seen it happen a few times. Usually it seems to be because the new cage didn't have proper hides but I've also seen it when moving from a small opaque cage to a large clear one. And I've seen them go right back to feeding when put back into a small opaque cage.

Like Frank said putting some of the former cage furnishings in(unwashed) and even some of the substrate from the former cage can help.
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