Post by kevin on Apr 28, 2019 11:45:00 GMT
You need a hole size of atleast 25mm (blue tit) I would recommend a 32mm hole though, This opens it up to Blue tits, Great Tits and Sparrows.
So gives the box a better chance of success.
I thought it was myself Paul, I’m so pleased we brought the subject up now. I will take the box down and check it over before widening the hole as I noticed a wasp going into to it the other day.