Amphibians

Male glassfrog photographed from below using a flash, showing its transparency
Male glassfrog photographed from below using a flash, showing its transparency

How glassfrogs become transparent when they sleep

During the day, glassfrogs hide under leaves and become almost transparent, leaving only their eyes, bones and internal organs visible. This camouflage is so effective that they can sleep peacefully during the day, in preparation for the night, during which they hunt for prey. 

Scientists have long wondered how glassfrogs are able to bring about their "cloak of transparency."

Lizard goes diving with an air “tank”

Bubble on the nose 

This extraordinary behaviour has been observed and filmed for the first time by ecologist Lindsey Swierk of Binghamton University, New York. “They are probably extracting lower concentrations of oxygen every time they’re respiring the air bubble, but it might just be enough to keep them underwater for long enough that they can escape a threat,” she said. Even though the bubble is relatively large, it remains attached to the lizard’s head rather than floating off to the surface.