The Roller Girls

Kelly’s Field Notes

Our guest on this episode is Dr. Scott Kight, the Associate Dean of Student Affairs for the College of Science and Mathematics at Montclair State University in Montclair, New Jersey. Scott was Kelly’s M.S. advisor and is on her doctoral committee! 

Scott’s Profile Page at Montclair State -

Scott’s ResearchGate Page -

Common Name: Roly-poly, Potato Bug, Wood Louse, Slater, Sow Bug, Pill Bug, and so many more!

Order: Isopoda

Suborder: Oniscidea

Species of Note (There are over 3700 species of terrestrial isopod belonging to 37 families):


Terrestrial isopods range in size from 8.5 mm to 17 mm (about 3/8 to 9/16 of an inch). In the wild, they are generally grey or brown in color. They come in two types: runners and rollers. Runners, often called sow bugs, cannot roll up for protection so instead tend to be very fast and fairly flat so they can slip into small spaces. Rollers, often called roly-polies, can roll up or “conglobate” for protection. Their cuticle (covering) is tougher than runners and they move at slower speeds.

Life Cycle:

Terrestrial isopods are crustaceans! While they live on land, they breathe through gills and require high humidity in their habitats. Life begins for a terrestrial isopod as an egg, carried in its mother’s marsupial pouch. Once they hatch the mother will carry her young in her pouch for about 2 months. Here they will feed on a nutritive fluid their mother creates. It’ll take about a year for the young to reach adulthood.


Terrestrial isopods have a worldwide distribution! They are found in most habitats, only missing from polar regions and high altitudes. They have been spread far and wide by commerce, for example they are not native to North or South America.

Super Powers:

Terrestrial Isopods in Culture:


“Armadillidium Vulgare.” Wikipedia, 18 Sept. 2020,

Hetzler, Paul, et al. “Pill Bugs: The Not Overtly Unpleasant Invasive.” NCPR, 4 July 2020,

“Pillbugs, Vol. 6, No. 24 | Mississippi State University Extension Service.”, Accessed 2 Dec. 2023.

‌‌“Porcellio Laevis.” Wikipedia, 27 May 2021,

‌Sfenthourakis, Spyros, and Elisabeth Hornung. "Isopod distribution and climate change." ZooKeys 801 (2018): 25.

“Sowbugs, Pillbugs.”,