Meet the Roly-poly

They don't bite, aren't slimy, don't slither, and to some of us, are rather cute. You have seen them in your backyard and they are known by several names: roly-poly, pillbug, wood lice or potato bug, to name a few. These tiny creatures can offer children a world of delight and discovery.

First consider these interesting facts. Roly-polies are not insects, but are crustaceans. This means they are related to lobsters, crabs and shrimp. They belong to a very ancient subgroup called isopods with most of its other members living in marine habitats. They actually breathe through gill-like structures and therefore must live in moist places. Some roly-polies are "rollers," that is, they roll up into balls when it is dry or they feel threatened. Others are "hikers" and do not roll into balls, but move quickly to escape sunlight and other threats. These isopods are decomposers who eat decaying leaves, wood and other vegetation. Roly-polies are cold blooded and molt as they grow. The females produce up to 200 eggs, which are carried in a brood pouch under their thorax. When the babies hatch, they are fully self-sufficient and look like miniature adults.

With simple materials such as a hand lens, stop watch, cups and spoons your child can pose simple questions and then test their predictions. Try placing a roly-poly on its back (test both rollers and hikers). Can the roly-poly turn over? Dunk a roly-poly under water for three seconds. What does it do? Hold a sheet of paper a couple of centimeters over the top of a table and place a roly-poly on top. What does it do when it gets to the edge of the paper? Lay out a piece of one-centimeter graph paper and make an "X." Gently set the roly-poly on the "X" and time it for 15 seconds. Count how many centimeters it crosses. How fast does it move? Your child can also test different objects to see which ones roly-polies prefer to hide under: wet cardboard, rotten wood, rocks, big flat pieces of sliced pumpkin and more. Also feel free to come by PEEC and use one of our microscopes to look at a roly-poly close up.

Remember while working with roly-polies that they are small and fragile. So they don't get crushed, transfer the roly-polies using a plastic spoon. Create a temporary "hideaway" while studying them, using a little soil and leaves in a plastic container. Be sure to put small holes in the lid and to keep the hideaway damp, not soaked.

Once children start getting to know these ancient creatures, they'll think of even more exciting questions to explore. As always, have fun discovering nature's secrets with your child.