Humping
Humping is a normal behavior for dogs- it could be people, animals or even objects. It isn’t a sexual or dominance issue, it’s often just a playful behavior. There is no harm in this behavior, but it can obviously get quite annoying and make other dog owners uncomfortable.
Sniffing Butts
As you know, dogs have a very strong sense of smell. They often sniff each others butts to learn more about their new friend. Dogs can tell gender, temperament and diet from just a few sniffs!