So, I was thinking today that pill bugs have a lot of legs. I figured they must not be insects. So, I looked them up to find out what they were, and Wikipedia says they're crustaceans. Then I found the following article:
It's very interesting, and I recommend reading it, but it has a few myths and/or partial myths in it.
Myth #1: Pill bugs aren't pests. Actually, pill bugs are sometimes pests (but please don't use pesticides on them). They sometimes (but rarely) chew on mature pepper, horseradish and potato foliage, and fairly commonly on seedlings of various species and such. They sometimes (but rarely) burrow holes in ripe tomatoes. They're not usually a threat to mature plants, whether or not they eat parts of them (pretty much just young ones). Nevertheless, it's a prevelant myth that it's a myth that pillbugs are pests. It is true that they perform beneficial actions, but gardeners do get distressed about their behavior at times. In my observation, they're more of an issue when the pillbugs are numerous and the plants are few. To deal with pillbugs, I just pick the ones I can find up at transplanting time and throw them somewhere else, and I remove the uncomposted organic matter that attracts them. I also overseed and wait a while after transplanting to thin the plants. Pillbugs don't usually bother plants (as often) after they're established, or if there's a big group of plants. Some people argue that the plants or fruits afflicted with pill bigs were rotting or would have died anyway, but I don't think this is always the case. They do target tender plants, however. Tougher plants shouldn't be bothered.
Myth #2: Pillbugs prefer humid environments. Well, this is and it isn't a myth. Pillbugs can live in semi-arid areas just fine, but they prefer to live under things where it's moist and dark. They like moisture (it's not a humidity thing, necessarily). While it's possible that they do indeed prefer to live in humid environments, they proliferate in climates where it's not humid, too.
Myth #3: Pillbugs can't survive in areas where it gets -20° F. or lower. My area gets that cold and colder (although not every year, certainly), and we still have loads of pillbugs.
Myth #4: Pillbugs aren't burrowers. Well, I don't know that they burrow holes to live in and stuff, but they're certainly capable of burrowing extremely well (better than most other burrowers, in fact). If you try burrying some in my garden, they'll dig their way out pretty fast, even if they're a fair ways down. Sometimes I incidentally burry them when I'm transplanting, and they burrow up out of the dirt. It's amazing, in fact. I think I've found them under the soil of their own accord, too, but I'll have to watch and verify that.
I'm skeptical about them dying when they're more than 30% dry. Ours seem to be able to handle more dryness than that. They can handle a lot
more dryness than slugs and snails.
It's possible that our pillbugs are a special species adapted to drought, burrowing, cold, and being pests. There are lots of species of pillbugs, and I imagine each species is different.
I'm curious how they taste now that I've learned they're crustaceans. Our toads eat them quite a bit, it seems. You never know when an animal has parasites or diseases you could catch, though, especially when humans don't usually eat it.