Why do dogs spin in circles before lying down?

Wild canids circle to flatten tall grass or leaves into a bed, push away rocks or insects and check for threats from all directions. Although domestic dogs have soft beds, the behaviour is hard-wired. Circling may also help a dog position its body to conserve heat or stay cool, depending on the weather. Some dogs scratch or paw at their bedding for the same reason. Occasional circling is normal, but excessive spinning or difficulty settling can sometimes indicate pain, anxiety or a neurological issue worth mentioning to a vet.