Husky (detailed introduction)

　　The sleep frequency of dogs is 45 minutes, exactly half that of humans. The body and brain repeatedly cycle through "REM sleep" and "non-REM sleep" states, with wakefulness and light sleep acting as a bridge. Generally, light sleep accounts for about 80% of the total sleep. Namely: 1. Drowsily entering sleep state; 2. Beginning light sleep stage; 3. Entering deep sleep; 4. Deep sleep, categorized into stages 1-4, which restores fatigue, relieves stress responses, strengthens immunity, and repairs damaged tissues; 5. Then, the body prepares to wake up.
　　Because dogs live together with humans, their life patterns are the same as their owners, so their sleep patterns are also similar. However, since dogs have a shorter sleep frequency than humans, the cycles happen more frequently. Even if an owner talks in their sleep to call the dog in the middle of the night, the dog will immediately respond, then continue sleeping.
　　If the owner's lifestyle is nocturnal and sleeps during the day, the dog will reverse its sleep habits accordingly. But this fundamentally disrupts the dog's internal biological clock. For the dog's health, such owners should consider changing their own lifestyle.