Hi Kevin and all
If you wish to stack three or four shallows on the tops of the hives, a
double thickness of newspaper between each will allow them to occupy as many
as they want.
I have done this to hives that I robbed of brood to make up nucs, the hives
were not tended regularly during the rest of the season.
I cannot be certain there was no swarming, but I never noticed any.
Best Regards & 73s... Dave Cushman, G8MZY
Beekeeping & Bee Breeding Website...
http://website.lineone.net/~dave.cushman