What is it about dogs and bum sniffing ?

Took blue for a walk last night and she meets all these other dog’s and all they want to do is sniff bums and run around in circles . . now thats the life to live, no money worries, no food worries, all you’ve got to worry about is when your next going to sniff a bum

Anyways here’s another video of Blue meeting her fellow Bum Sniffers