Marie and Michelle explore the California Cavern to discover how speleothems vary with differing conditions in the cave. Gillian considers the properties of two neighboring lizard habitats to understand why lizards are numerous in one and not the other. Susie and Katie investigate what's causing the malformations at their neighborhood frog pond. Biologist Erin Gilliam uses a “virtual bat,” which is a technology that mimics real bat sounds and calls.

Originally released by Big Media Holdings LLC, 2013. Streaming video file encoded with permission for digital streaming by Infobase on February 10, 2017.

Deep Dark Down (6:23); --Reptiles (5:44); -- Bat Biologist Erin Gillam (1:49); -- Freaky Frogs (5:32); -- Credits: World of Reptiles: Dragon Fly TV (0:48); .