In order to maintain the integrity of his organic garden in the Pacific Northwest, designer Alex English used to trap the slug population in his garden using an empty tuna can filled with beer. He soon came to the same realization that all gardeners do when they create slug traps with a tuna can: Slugs are most active after rain, and with a good rain the beer is washed out of the tuna can -- making the trap ineffective.
To address this, Alex fashioned a roof for his trap by cutting an aluminum can to keep the rain out the beer. Wanting a more attractive and safer slug trap (no sharp metal edges) he designed and 3D printed this beautiful garden slug trap.
It features gently sloping sides that allow the slugs to easily climb to their drunken death and a removable roof that keeps out rain.
While talking to Alex about his 3D printable Mason jar lids I mentioned she should combine his slug trap idea with the Mason jar lids for a truly large slug trap. For now, he mentions that working with the SCAD file you can adjust the dimensions of his slug tap to effectively trap larger slugs. You can download (for free) the file to 3D print the slug trap at Thingiverse.
Don't have a 3D printer? See the post on the Mason jar lids for tips from Alex English on how you can 3D print in your neighborhood or from the comfort of your computer.