From: "Dave Cushman" <dave.cushman@lineone.net>
Reply-To: "Dave Cushman" <dave.cushman@lineone.net>
Date: Sun, 10 Jun 2001 12:07:10 +0100
To: <BiologicalBeekeeping@yahoogroups.com>
Subject: Re: opening size

Hi all

Helmut makes a good point...

20 years ago I decided that 8 mm (5/16") was small enough to keep mice out.

It worked successfully until last winter, when I had one mouse get in.

However the failure rate is small, this one instance occurred in about 540
successful ones.

The floors concerned had a hinged flap as an entrance which could be closed
using a wingnut, but the 8 mm gap was set during manufacture using a gauge
piece and then blocks were glued and screwed at each end of the flap to
limit the opening to maximum of 8 mm.

My other floors that have 22 mm entrances are rendered mouse proof by
inserting the queen excluder between the floor and the brood box.

The 1000 square mm figure originated from a study of wild nests in hollow
trees.

Regards From:- Dave Cushman, G8MZY
Beekeeping and Bee Breeding, http://website.lineone.net/~dave.cushman