The reasons why dogs suddenly keep whining at night:

1. A thief is coming. A dog's hearing is much more sensitive than that of humans, and it will immediately become alert as long as there is any disturbance outside. When the dog hears the footsteps of a stranger approaching the house, sneakily, the dog will immediately bark in an attempt to scare the stranger away.

2. There are mice in the house. If there are rats sneaking into your home, the dog will also bark in the middle of the night, and will keep chasing the direction in which the rat runs. In this case, the owner can determine that a rat has entered the home.

3. In a bad mood. Dogs also have small emotions. When they are scolded by their owners or encounter something unhappy, they will be very sad and howl in the middle of the night to vent their emotions.

4. Physical discomfort. Dogs also like to bark when they are not feeling well, and this is no exception in the middle of the night. Dogs will be listless and whine.

5. Discover danger. If the dog discovers a fire, gas leak, etc. in the home, the dog will detect and alert the owner in time because of the dog's excellent sense of smell.

6. Not adaptable to the environment. After arriving at the new home, it will keep making whining sounds because it has just changed to a new environment and feels strange and scared.