Solutions to the problem of puppies not sleeping at night:

1. You can solve the problem by playing more games with the puppy during the day to consume the puppy's energy.

2. You can also place it next to its owner to sleep, or place it in a small space to give it a sense of security and let it sleep.

3. You can also buy your puppy more toys that it likes to play with, so that it can consume its own energy and feel sleepy at night.

Reasons for puppies not sleeping at night:

1. Puppies that have just entered the house are probably because they are unfamiliar with the environment and family, and are not accustomed to it. And I feel scared and afraid, so I don't sleep.

2. If the puppy is suffering from a disease, it may also be unable to sleep due to physical pain.

3. Because the puppies have not developed good work and rest habits, the puppies do not sleep on time at night.