When you try to generate a bee nest from a sapling with a flower next to it, the hive will always have no bees in it.

Steps to Reproduce:

1. Place a sapling (oak or birch) next to a poppy (or any flower)
2. Bonemeal the sapling to grow
3. Repeat the prosess until you get some trees with bee nests

Observed Results:
When the time is day and there is no rain, no bees will come out of any nest

Expected Results:
Bee nests generated from a sapling can have 1-3 bees (From the official minecraft wiki)

Notes: It might take some tryes to get a bee nest so be pacient and try again.