Bearded Dragon What Triggers Sleep. Reptiles need it to be warm to function. Try leaving a light on so that they realize it is daytime.
Some bearded dragons will sleep during the whole brumation period without waking up, and some will take long naps off and on. When a bearded dragon is in a heavy sleep, their metabolic and respiratory rates significantly drop. A bearded dragon that darkens its body or beard is typically one that is either cold, angry, scared, stressed, ill, or threatened.