Thanks for the tips.

I'm glad the beer trap doesn't get full marks - I was always a bit
reticent about wasting good brew....

I think I'll definitely go for the plastic shelter idea (in
combination with some sort of irresistable slug snack treat). So, one
final question. Assuming the slugs do congregate under the black
plastic, what is the best time of day to remove them? Morning, after
their midnight feast?

Lawrence