> Can someone give some insight as to the better size before I build them
> with the wrong size screen?

Honey bees can get through.Anything with more holes per inch than 6-mesh 
(6 holes per inch).  In fact, I used 5-mesh hardware cloth sheets as 
queen excluders on 2-queen Farrar hives for years, since 20x20 excluders 
were not available.

Some normal bees, but AHB in particular, can get through 6-mesh.  Also 
consider any wasps or hornets in your region before deciding.

If robbers can easily get through, then the whole hive bottom is open to 
robbing.  That may not be a big problem for strong hives, but weaker 
ones may be robbed out.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm