paghat wrote:

"Beer traps do attract slugs but don't reliably kill them unless the trap
is deep enough slugs can't reach over the top to get out (so saucers don't
work, slugs climb right off the saucers, but Yoplay yogurt plastic cups
are just barely too deep for a slug to climb out of, so it drowns in the
beer). Such a trap would also endanger frogs & small lizards & beneficial
insects that per chance fell in, without really resulting in a dramatic
lessening of the slug population."

Ok, here's a solution that fixes both the depth and reptile problems.
Put a lid on the container and punch holes in it, large enough for
slugs to get through, but small enough so your wild reptiles won't
accidentally fall in. The bottle on its side also accomplishes the same
thing. And in my experience, the beer doesn't have to be too deep to
drown the slugs.