Scruffy's scratching the floor before lying down may leave you scratching your head as you try to figure out the reasoning behind this behavior. While your dog can't talk and give you an explanation, a step back into your dog's past in the wild can provide some insight. Despite domestication, many doggie instincts have survived and the scratching the floor ritual is one of them.
Keeping Critters at Bay
While your pampered pooch may wear fancy collars, eat fancy food from a can and sleep on a designer bed, he still retains instincts from the wild. In the wild, before being domesticated, canines used to sleep in the open where they often shared the environment with other small critters. The habit of scratching the floor before lying down may therefore derive from the need to scare away any unwanted critters. No dog, after all, would want to share his bed with spiders or snakes.
Creating a Comfy Bed
Another possibility is that dogs used to scratch and turn around several times to create a comfy bed. Before the invention of doggie pillows, wild dogs used to sleep on different surfaces, including dirt and fields with tall grass. By scratching the ground and turning around several times, the dog was able to flatten down the grass or possibly gather leaves and moss to create a comfy spot to sleep. Also, the scratching may have helped keep sticks and stones out of the way.
Keeping Cool or Warm
Before being domesticated and welcomed into a human's home, wild dogs had to find creative ways to cool themselves down during the hot, summer months. With no access to air conditioners and fans, canines relied on cool dirt to get some deserved relief. This often entailed digging up a hole to sleep in or simply scratching the surface to expose a cooler layer of dirt. On the other hand, dogs living in cold areas may have instinctively dug shallow beds, which were a considerably better option than sleeping on the ground's surface.
Besides scratching in an effort to plump up their sleeping areas, cool off and scare away nasty critters, dogs may also scratch to claim their territory. Dogs have sweat glands on their paws that leave a distinct smell that can be easily detected by dogs courtesy of their powerful sniffer. This bedtime ritual may therefore be triggered by a need to tell others "this bed is mine."
Reducing the Behavior
While there's no grass and hopefully no unwanted critters in your home, the scratching behavior survives today in many dogs. If your dog's scratching behavior has damaged your carpet and created ugly holes on your couch, you may want to reduce this behavior. Providing your dog with a comfy dog bed he can call home may help. Many dogs prefer circular beds with raised edges where they can rest their head, according to the ASPCA. Rewarding Scruffy often for lying on his bed will help him make good choices so your carpet and couch can thank you.