Disappearing Bees from Bee Nests

Collecting Bee Nests using Silk Touch and placing it back down seemingly causes bees that are inside to disappear.

I collected two nests with my silk touch pickaxe, one with 3+ bees (earning the achievement) and one with at least 1 bee. When I returned to my base I placed both down, and neither has shown any bees exiting the hive.
I don't want to break the nests without Silk Touch, because I'm afraid that it might remove the nest entirely leaving me with no bees and no proof of nests.