I would assume it would be the same as raising a ball python on only mice. The snake would be smaller overall. Eventually one larger meal just makes more sense and it easier for you.
Yeah, there are snakes out there that will not touch rabbits, and as a result one has to result in feeding multiple xxxl rats per week. While ultimately cost effectiveness is negligible given prices of bulk rabbits compared to rats, it is doable.
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Retics are my passion. Just ask.