A big reason why children get nipped and bit by their puppies is because their movements and mannerisms can look and act very similar to a toy, a game or another puppy. What do I mean by that? Dangling hands and feet, fast moving appendages, squeeking, squeeling, running, basically all the things young children do can look like a toy or game to young puppies.
Well, do we just shut the kids in a crate? No, that’s illegal apparently, even if some children enjoy being in the dog crate. We have to teach kids how to move and act around puppies and we have to teach puppies not to target children with their mouths. With very young children, contact should be limited, and containment and supervision are a MUST. Leashes, xpens and crates are essential when a puppy lives with very young children.
With older children it is imperative to teach them that they can control their puppies energy and actions by how they behave and what their energy levels are like around the puppy. In the video below, you will see a quick example of how simply climbing over a barrier can either entice biting or encourage polite behaviour out of a very young puppy. You will see that dangling and fast movement entices chase and bite reflexes (especially in higher drive puppies) where as deliberate calm action, and stillness can inhibit those reflexes and encourage the correct behaviour.
All that said, both kids and puppies are not robots. The do things daily that we think “oh my god, how many times have we been over this?”. Both kids and puppies (and some adults) need reminders and help along the way. They need direction in order to succeed and many times that direction has to be repeated on a continual basis, and that’s ok. That’s life, that’s how all creatures learn.