Minecraft wiki entry for Honey_Block, associated text: Honey blocks are not full blocks: despite taking up 163 pixels, the collision box is only 14×14×15 pixels.
The bottom face of the honey block is the same depth as a full block, though it is only 14×14 pixels.
Small entities such as arrows are free to move through the gap between honey blocks as they are under 2 pixels wide.
Only when entities are partially "in" the honey block (i.e., they are touching the 143-pixel hitbox) can they slide down against it.
In real life, bees eat honey when the temperature is low and flowers are difficult to find. Otherwise, pollen and nectar are their primary food sources.
The bottom surface of the honey block does not slow down entities.
It takes 1 minute and 14 seconds to slide down 256 honey blocks.
The player cannot place some blocks on the honey block such as vines, ladders and torches.‌[Java Edition only][2]