its nesting, getting comfy
...and I'm going to add... that the Dog is flattening the grass, ground, snow.. or whatever... and instinctive behavior.
thumbs up wayswin. inbuilt instinct.
needs to go pee, pee or he wants a biscuit for showing you his new trick !!
going to sleep.
hes got worms.
Tired of going in circles and wanted to sit.
Dizzy or drunk ;+)