opening for bees at the bottom board?

[bayareaartist]

I am building my first hive and I was wondering about the opening to let the bees in.
I am loocking at the beesource pdf file and it shows 3/8 of an inch, I am spot on that but it seems to be not very much room.
Is this ok?

and for an entrance reducer how big should the opening be when it is installed?

thank you.

[Robo]

The beesource bottom board is reversable.  Use the 3/4" opening in the summer, flip it over and use the 3/8" opening in the winter (reduced).  No need to use a reducer block.

[Michael Bush]

It's all relative.  The entrance can be as large as 3/4" and as small as 1/4".  An entrance reducer can be as small as 1/4" and it will slow down robbers a lot, but also slow down traffic.  If a hive is getting robbed, the slow down is a good thing.