It's just a dog thing. It has to do with sharing their food and allowing others to get a bite.
However I'm not sure if it is learned (when sharing food with litter mates after weening) or if it is instinctual (members of the wolf pack had to take turns getting something to eat after killing their prey).
__________________ Life is merrier with a Yorkshire Terrier! Jezebel  & Chuy ... RIP: Barkley  Loosie & Sassy  |