I don't know if they require refrigeration either... I left mine in a rubbermaid w/o a top and all the Mulberry I could find... room temp (75F ish). They did fine and no one complained
I think I actually went through more than the 60 initially, though... and the funniest thing was watching my rattie gang go NUTS BONKERS for 'em.
When you order them, ask how they keep them... or just order enough to feed your guys once. They are on the expensive side... for me, they were, anyway. The guy tried to charge me a quarter a piece, but he had already quoted me $0.15 before they arrived and he chose to honor that.
Sorry I'm not much more help. They were a treat for my gang actually, cuz I splurge on all their organic fruits and veggies on a regular basis as it is.
"Lots of people talk to animals. Not that many listen though. That's the problem."
- Piglet