Hands-on activity that provides practical application/simulation of population density studies. Students learn how "species counts" are performed by randomly counting "pill bugs" using rubber band tosses and "rbu" (rubber band unit) land area estimates. A fun activity that solidifies learned material during an ecology unit. Teacher instructions for simulated pill bug habitats (no actual animals are harmed (or used) during this simulation) in step by step detail included. In addition, a sample poster "habitat" demonstrates re-usable materials for year after year enjoyment.