'Ah, here it is'

I wonder what it is that makes dogs pick a particular spot to do what dogs do that we have to pick up.
Foxy doesn't spend any time searching, when you've got to to you've got to go. Jonty, on the other hand, spends ages going around in circles, sniffing all over the place, until he finds just the right spot. Only when he's happy does he settle down to do it!