I've used Sluggo for forever and never seen a snail, altho I have had to pick some slugs off the bottoms of pots, which just rewards the little devils with more Sluggo UNDER the pot. I've had very few of those pill bugs - I call them roley upey bugs, but now that you mention it they disappeared after I applied Sluggo to that area. I started using it because Annie @ Annie's Annuals recommended it and it works.