Murdering pests

I've come to the conclusion that it's been slugs and ground-based creatures eating away at my crops - while I haven't caught any at it, some of my crops inside the vegetable cages and under cloches have been eaten, which rules out cats, birds and anything else that wouldn't already be present in the soil. Current best theory is slug eggs and overwintering caterpillars in the compost, which enables them to pop up under cloches.

I'm adopting several plans of attack. The first is to cover the area with non-toxic slug pellets, which double as poison and an alternative food source. The second is to go with preventative measures on really vulnerable plants; I've replanted the mange tout with woollen pellets covering the soil which apparently slugs don't like going over and I've attached copper tape around the side of the pot, which reacts with the slime on their foot to produce electricity.

Burn, you insufferably terse dullards!

One of my esteemed commenters and good friends suggested crushed egg shells on the soil and even kindly offered me a jar that she'd prepared earlier. I turned her down in favour of the wool pellets - while I plan on eggshelling around my spinach, I don't think there are enough eggs in the whole city to evenly cover my expanding vegetable beds and a jar's worth wouldn't even get me a sixth of the way round the garden.

The first two methods of pellets and protection are good, but they lack something. You can tell they've worked because your plants are still alive, but they don't have that special sense of vengeance that I'm looking for. I want corpses that can be used to warn others of the perils of raiding my vegetable garden.

I want to see their heads mounted on a spike outside the house, so I can wave at them, like this. Can you arrange that for me?

Beer in a pot is a time-honoured way of murdering slugs and it's given a little high level of professionalism by a Christmas gift from my brother-in-law-in-law-in-waiting.

 The fiance of my wife's sister, in case you were wondering.

I don't know how much they cost, but I may need to get some more - the lid give protection from the elements and it's designed just right to give the little gits the feeling that they're coming in for a shady snack before finding out that it's actually their doom. Only problem I can foresee with them is the cost of changing the beer - does anyone know how often it needs to be done? Those two traps used up one can of Sainsburys basics lager and while the stuff is only £1 a go, if it needs to be changed every week, it'll add up.

PJW