Our archive has an external glass door facing a footpath which is about 20cm from the secure internal door. The location means we can’t have conventional blunder traps, as the boss thinks they’re ugly.
Our current solution is a perspex sheet cut to size which is spread with horsefly glue. The glue is regularly scraped and replaced, and the trap is not too visible.
However, this is a sticky and sometimes messy solution so I’m wondering if anyone has any better / different ideas?