24. They start early

Katribe claimed that puppies need to stay with their birth family till they grow past the age of 7 weeks because they need to attain a certain level of psychological development through their interaction with their mom and siblings. "The ones that are separated from their mother and litter earlier are more prone to behavior disorders, including separation anxiety and increased fear responses," the doctor explained. "Puppies that remain with their mother and litter longer, particularly if they're being exposed to new experiences, tend to respond better to novel experiences later in life and become better-adjusted pets."

However, there are puppies that are specifically bred to be sold at pet stores, and they are separated from their birth families at a young age and then housed in a kennel with a limited view of the outside view, due to which they find it difficult to socialize.