I ran a bunch of tests many years ago with mice and the type of feed I planned to use.
To make a long story short, I simply found the mice really, really struggled to eat through the 1/4" mesh. But I've also seen numerous anecdotes on these forums saying they can eat fine through it. For my piece of mind I'd use 3/8" or 1/3" - both are very close in size.
Even better, it also works very well for rats.
If you have to order it in bulk don't worry about having excess. I have found it's VERY easy to sell the surplus to other breeders. In fact you might even pocket a few bucks once all is said and done.
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Current snakes:
0.2 Gonyosoma oxycephala - (Silver/Yellow)
3.3 Gonyosoma oxycephala - (Green)
2.1 Gonyosoma janseni - (Black)
3.3 Gonyosoma janseni - (Black & Tan)