If a bee is pressed up against a block, they can clip through that block right as they age. Once they fly through it, it appears that they cannot clip through it any longer. It is possible that this only works with 'transparent' blocks such as glass. Often, a child bee will do this on their own, with no assistance from the player.
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Thank you for your report!
However, this issue is a Duplicate of MC-9568.
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