The beagle can claim one of the longest lineages of any dog breed, stretching back to ancient Greece. Their highly developed sense of smell made them prized hunting dogs, and today their amiable disposition makes them popular pets. Active, friendly, and alert, beagles love exercise and company. They tend to prefer living in packs, but if they are a home's only pet, they will consider the family to be its pack. Beagles require mental stimulation and can't be left alone for long periods of time without some kind of activity; without the activity they can become bored and resort to destructive behavior.