Slug X Slug Trap

Bought one of these recently for £6. Have seen lots of slugs in the soil as I prep the garden for next year, and some of my ferns, heucheras and bergenias are being eaten already in Feb. The trap is made from recycled plastic and measures 26x21x6cm in size, with a removable lid. It's designed to sit on a fairly flat surface, with the two long sloping edges in contact with the ground so the slugs can enter. Unlike home made beer traps where the slugs fall in and drown, this is designed to lure them in, where the tight space above the beer pots leaves them overcome by fumes, unable to escape, more often falling into the beer pots. In use, place the trap where you want to leave it overnight and fill the 3 pots with beer (I find a stubby beer fills all 3 perfectly) and replace the lid, and unless the pots are full of slugs, I've used that beer for a week and just moved the trap around the garden. You could even sprinkle some slug pellets inside to further attract, but if any slugs escape after eating them, they are then ofcourse a threat to wildlife (wildflife friendly pellets are available now). One of the selling points of this trap is that it does not harm wildlife. In my experience it works well but mostly with smaller slugs, I've caught something like 30 in one night. Whether the big slugs come but are not overcome and able to escape I'm not sure. Emptying is the worst problem as you just have to tip them all out sideways (I flush mine down the loo) and then rinse the unit out for refilling.The other main problem with the unit is it needing a flat surface. I thought my garden borders were flat but invariably the trap only touches the surface in 3 or 4 places, which could perhaps be changed with some home made adaptions or packing some soil into the gaps. Slugs and snails are pretty smart anyway so they still find their way in. Overall I like it, you don't have to dog holes for it and it's working pretty well.