Overtired does not always look sleepy
Some puppies become faster, louder, and more mouthy when tired. They may grab clothes, chase feet, zoom through the room, and reject toys they normally enjoy.
The pattern often has a rhythm
If biting appears after visitors, training, a long walk, evening play, or several hours awake, fatigue may be part of the trigger. A short diary can reveal a predictable window.
Rest needs a transition
Moving directly from frantic play to confinement may create more frustration. Lower the lights and activity, offer a toilet break, provide a safe chew if appropriate, and guide the puppy toward a familiar resting place.
What to avoid
Keep the response gentle.
Avoid adding more vigorous play simply because the puppy appears energetic.
Safety boundary
When to get more help.
Sudden restlessness, inability to settle, or touch sensitivity can also reflect discomfort. Contact a veterinarian when the change is unusual or persistent.