Similar to "prairie-dogging": When a turd leaves it's nest, sees it's shadow, and runs back in. This is a precursor to the "turtle-head", and should not be taken lightly. Short yet expedited steps in the direction of the nearest toilet facility are recommended immediately. A post-evac check of the surrounding areas will signal a possible 6 week extension of gastrointestinal discomfort.
Jay- "dude its like the stage before ... like its not prairie dogging yet...its like right before that."
Greg- "Oh! So its ground-hogging ! It popped out saw its shadow and ran back up in there."