I am the owner of the very first species to be domesticated, a dog.
I also have dogs. Mine are worker dogs so they herd.
What type of dogs are considered worker dogs?
Dogs that require jobs, sometimes they are  on the smaller/medium end of size.
I believe it is due to their behavior and internal and external stimuli.
That makes sense, mine were bred to herd and have the tendency to bite at ankles.
Why do you think they bite like that?
They were conditioned and have a fixation due to the mix of breeding over the years, they are part dingo.
What is a dingo?
A dingo is the equivalent of the North American wolf, butin Australia.