I found this guide very useful and basic - a couple of photos at the end of what mine looked like. There is a lot of wet weather forecast in Ireland this week - so slugs and snails will be out in abundance.
HOW TO MAKE YOUR OWN SLUG TRAP• Large yogurt container with lid – emptied and cleaned
YOU WILL NEED:
• Inexpensive beer or non-alcoholic beer
WHAT TO DO:
1. Cut two holes (slug entrances) in the upper half of a large yogurt container.
2. Pour about two inches of beer into the container.
3. Dig a hole near your garden that is as wide as the container. Make the hole deep enough that the slug entrances will be at ground level.
4. Place the yogurt container into the ground so that the entrances to the container are flush with the ground.
5. Put the lid on the yogurt container (so dogs and raccoons don’t get into it!).
6. Check the trap after a couple of days. Throw away or compost the dead slug bodies.
7.After about two days the trap doesn’t “smell” and won’t attract slugs.Add more bait and try again.
HOW DOES IT WORK?Slugs and snails are attracted to the smell of the beer. They crawl to the trap, reach in and try to drink, fall in and are drowned.
This is what I used - an old milk plastic bottle and a large yoghurt container.
In place - as you can see the level of the soil is level with the opening. The shots are a bit poor as I was burying them in the corners where the snails and slugs like to reside in the raised bed.