Butchy boys, timberpigs, granny greys. Whatever you call them (regionally it varies quite a lot!), pill bugs are one of the most common critters in gardens worldwide. Personally, I called them roly-polies when I was a kid exploring my backyard.
I remember poking them and being dazzled as they rolled up into perfect little balls, a reaction I am sure many of you can relate to. But the reasoning behind this behavior is not just defensive, it is actually a historic reminder of their beginnings—the sea.
Pill bugs aren’t bugs at all. They’re terrestrial crustaceans – related to shrimp, lobster, and crabs! Millions of years ago, much like our ancestors, ancient pill bugs decided to walk out of the water and establish a place for themselves on land.
Though pill bugs are super successful as far as survival goes (they can found in nearly every climate aside from the Artic), they still have to combat features of the past. Gills. Yes, these small, land-dwelling armadillo looking critters have gills!
Unlike how their other garden roommates breathe, pill bugs have adapted gills on their underside that help absorb oxygen from the water held in damp soil or leaf litter. When they are in too dry of areas, they roll up to keep their gills from drying out!
Not only does staying in the depths of the dirt help them breathe, but it is also where they do most of their munching. Pill bugs feed on just about everything –from decaying plants to other insects to fungus. They’re good recyclers too. Everything they eat gets digested and returned to the soil.
The fungi in their diet may be the most important part. They are able to eat and digest basidiomycetes, fungal cords that help form root-like structures underground. These cords do a whole lot of good, stimulating plant growth and helping break down detritus.
However, too much of a good thing almost always causes problems. As they decompose dead leaves or rotting wood, it releases carbon dioxide into the air. As the planet warms, the amount of this complex fungi increases, and so does the carbon it releases.
But have no fear! Pill bugs are here! A group of researchers at Yale University’s School of Forestry and Environmental Studies conducted a study, that argues that these small, sea-to-land, wood shrimp help counteract the effects of the carbon released from forest soil.
By eating this fungus, they accomplish the deed of decomposing dead matter but eliminates the release of extra carbon into the atmosphere.
So, the next time you’re in the garden and see a small pill bug milling around as they do, be grateful they’re helping the earth in the small ways they can.
