Puppies are natural chewers and biters, and biting is a normal part of their development. However, it is important to differentiate between normal play biting and biting that may be a sign of aggression. Here are some signs to look out for to determine if your puppy’s biting behavior is normal or a sign of aggression:

1. Context of the biting
Consider the context of your puppy’s biting behavior. Puppies often mouth and nip during play, which is normal behavior. However, if your puppy is biting in other contexts, such as when you are trying to groom them or when you approach them with food or toys, this could be a sign of aggression.
2. Body language
Pay attention to your puppy’s body language when they are biting. Playful biting is usually accompanied by wagging tails and relaxed body language. Aggressive biting is often accompanied by stiff body language, raised hackles, and growling or snarling.
3. Bite strength
Consider the strength of your puppy’s bites. Normal play biting should be gentle and not cause any pain or damage. Aggressive biting, on the other hand, can be very hard and may cause injury.
4. Consistency of behavior
Consider the consistency of your puppy’s behavior. Normal play biting should be sporadic and usually stops when you withdraw attention or redirect their behavior. Aggressive biting, on the other hand, can be more consistent and may continue even when you try to redirect their behavior.
5. History and breed
Consider your puppy’s history and breed. Puppies from certain breeds, such as Pit Bulls and Rottweilers, may be more prone to aggression. If your puppy has a history of aggression or comes from a breed that is known for aggression, it is important to be vigilant and seek the help of a professional trainer or behaviorist.

In conclusion, while biting is a normal behavior for puppies, it is important to differentiate between normal play biting and biting that may be a sign of aggression. Consider the context of the biting, your puppy’s body language, the strength of their bites, the consistency of their behavior, and their history and breed to determine if their biting behavior is normal or a sign of aggression. If you are unsure, seek the help of a professional trainer or behaviorist to assess your puppy’s behavior and provide guidance on how to address any issues.