Why Dogs lick their bed or where they are going to sleep is the
same reason why the will sometimes scratch where they plan to lay
down. The scratching is a throwback to their wolf days, sleeping on
the ground, a dog will scratch the ground and sometimes dig a large
hole so that they can find a cool layer to lay on. In modern times,
where they can't scratch down to a cooler layer, they will lick the
carpet or bed to cool off their place of rest.