OurScott is right - slugs love a bitter or stale beer. Here is a site that has an overview of slugs and how to control them. Look at #6 Trapping. It's the slug saloon. http://www.gardenadvice.co.uk/howto/pest…
No insecticides please, they kill beneficial critters, too. Here's another site with more info http://gardening.yardener.com/ControlSlu…
You have slugs and a slugs very favorite food is Hostas. You can make slug saloons, a cap full of beer. they can't resist, get drunk and drown. Google it if you don't believe me.
Suppose you look at the Hostas and not the holes, each time you kill an insect in the garden you break the food chain, also something eats those poisened insects they die also, and so on until the birds die. It is well to remember the lesson of the eagles, they almost became extinct because men used ddt to kill insects. See if you can buy Mantis eggs for your yard then nature takes care of the problem. (( B))
Sounds like leaf cutters, either ants or bees. You should be able to get something at your local hardware or lawn and garden shop.