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7 Reasons Your Duck or Duckling Might Be Opening Its Mouth

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Ducks and ducklings are fascinating creatures with unique behaviors. A common behavior you can observe in these waterfowl is the opening of their beaks or mouths.

While it may seem like a simple action, there are several reasons why your duck or duckling opens its mouth.

A duck or duckling might open its mouth because of heat stress, dehydration, and respiratory infections. Other common reasons are excitement, sinus issues, digestive problems, and swallowing.

While the behavior can be a concerning observation, understanding these reasons can help you better care for your feathered friends.

Read on to have a better understanding of your duck’s behavior and be able to identify any potential issues.

Duck photograped with open mouth sitting on the grass

1. Your Duck Is Responding to Stress

Like other animals, ducks can experience stress in various situations.

Stressful situations for ducks can result from illness, encountering predators, lack of food, changes in weather, or being in a new environment. 

You can tell that your duck is stressed if you notice the following behaviors:

  • Poor appetite
  • Restlessness
  • Excessive grooming or preening
  • Aggression
  • Lethargy
  • Avoiding contact with other ducks
  • Ruffled feathers
  • Listlessness

According to one study by Dr. Karen Machin of the Western College of Veterinary Medicine, prolonged stress in ducks can weaken the immune system, lower cognitive ability, and even affect growth.

When ducks feel threatened or uncomfortable, they may open their mouths as a response. 

For instance, ducks may open their beaks in hot environments to regulate their body temperature when experiencing heat stress.

This means it’s crucial to ensure that the temperature is always appropriate for ducks and ducklings, as overheating can lead to heatstroke. 

2. They Have Respiratory Infections

Duck with open mouth sitting on the shore

Respiratory infections are common in ducks and can cause various symptoms, including difficulty breathing. 

One observable behavior often seen in ducks with respiratory infections is opening their mouths. 

This is a natural response to try and increase the airflow to their lungs to alleviate the discomfort caused by the infection.  

Infections that affect the respiratory system, such as aspergillosis, are associated with hyperpnoea, with panting, wheezing, gasping, coughing, and cyanosis.

Aspergillosis is caused by a fungus called Aspergillus, which can grow in damp and humid environments. Ducks in dirty and poorly ventilated environments are more likely to develop aspergillosis. 

It’s vital to provide your ducks with a clean and dry living space with good ventilation to prevent the onset of this disease. 

3. They Could Be Dehydrated

Another reason your duck or duckling is opening its mouth is that they are dehydrated.

When ducks or ducklings become dehydrated, they may pant, which is the act of opening and closing their beaks rapidly. 

Here is a video of ducks panting:

Panting allows air to flow across the moist surfaces in the mouth and throat, which can help reduce body temperature. 

Opening their beaks and panting can also help ducks increase their oxygen intake, which is essential for survival. 

4. The Nostrils Are Blocked

Curious duckling with open mouth standing on the grass

Ducks have unique adaptations that enable them to thrive in aquatic environments. One of these fascinating adaptations is their ability to breathe even when their nostrils are stuffed.

This is achieved by opening their beaks and inhaling air directly into their respiratory system. This adaptation allows ducks to continue foraging in aquatic environments.

5. Digestive Issues

While indulging your feathered friend with extra treats or meal portions may be tempting, it’s important to remember that ducks have small stomachs and delicate digestive systems.

A study on the influence of diet on mule duck behavior reveals that overfeeding your duck can influence behaviors such as increased panting and decreased walking and preening behaviors.

This could account for your duck or duckling opening its mouth.

If you notice your duck panting or struggling to breathe after eating, it’s time to cut back on the feeding and consult a veterinarian for advice.

6. It’s a Sign of Excitement

Happy Small yellow duckling on green grass

There are specific actions that may communicate how your duck or duckling feels. Ducks make different sounds and expressions when in particular moods, and opening their beak is one of them.

Here is a video of an excited duck:

When happy, a duck may flap its wings, bob its head, quack loudly, or even open its mouth to express excitement. 

These behaviors indicate the duck’s heightened arousal and enthusiasm and can be seen during mating rituals or when they are about to eat. 

However, not all ducks open their mouths in every exciting situation. Each duck is unique and may express excitement in different ways.

7. They Are Swallowing

Mallard duck swimming on water with open mouth

It is a common observation to see ducks opening their beaks wide while consuming food or water. This behavior may seem odd, but it is crucial to their digestion process. 

Ducks do not have teeth and rely on their bills to grasp and swallow food.

Opening their mouths wide creates a vacuum that helps draw water and food into their mouths, making it easier to swallow. 

This behavior is critical when consuming aquatic plants that can be tough and fibrous. Opening the mouth is a necessary adaptation for their survival.


How Do You Know If Ducklings Are Too Hot?

You know that ducklings are too hot if they are panting, stretching their necks, or spreading their wings away from their bodies.
Additionally, if the ducklings are huddling together as far away from the heat source as possible, it may suggest that they are hot.

Why Does My Duckling Look Like It’s Panting?

Your duckling looks like it’s panting because it is either dehydrated or overheating.
Ducks cannot sweat since they don’t have sebaceous glands, so they rely on panting to regulate their body temperature. Therefore, if the temperature is too high, your duckling may pant to cool down.


Understanding why your duck or duckling is opening its mouth is crucial in monitoring their health and well-being. 

While some reasons may be harmless, such as cooling down on a hot day or communicating their emotions, others may indicate a more severe issue, such as respiratory distress, digestive issues, or dehydration. 

If you see your duck or duckling opening its mouth, look closer and see what it might be trying to tell you.