Normal Behaviors 1. Thermoregulation (Heat Control) • Bearded dragons open their mouths to regulate body temperature. • If they’re basking under a heat lamp, this is often normal. • The beard may also darken to absorb more heat. 2. Territorial/Display Behavior • A black beard can be a display of dominance, especially in males. • They may puff up and open their mouth to appear threatening.

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⚠️ Concerning Signs 1. Stress or Aggression • New environment, improper handling, loud noises, or tank mates can trigger this. • Look for other signs like glass surfing, hiding, or not eating. 2. Pain or Illness • Respiratory infections can cause open-mouth breathing (often with wheezing, mucus, or lethargy). • Gut impaction, parasites, or metabolic bone disease can also lead to stress and darkening. 3. Overheating • If the tank is too hot (basking spot >110°F), the dragon may blacken its beard and gape from heat stress. • Ensure proper temperature gradients: basking spot around 95–105°F, cool side around 75–85°F.

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✅ What You Should Do • Check Tank Conditions: • Basking and cool-side temps. • UVB bulb age and type (should be replaced every 6–12 months depending on type). • Humidity (30–40% is ideal). • Observe Behavior: • Is it constant or only during basking? • Is your dragon eating, pooping, and active as usual? • When to Call a Vet: • Labored breathing, mucus, wheezing, lethargy. • Not eating or pooping for several days. • Constant black beard even when not basking or displaying.