Location: Arctic Tundra, North America
Average life span in the wild: 6 to 8 years
Average weight: 40 to 175 pounds
Wolves are the largest members of the dog family. Contrary to legend, wolves don't howl at the moon. But they're known to howl more frequently when it's lighter at night, which often happens during a full moon. The wolf has a complex communication system, and a howl might pinpoint pack location or warn of territory boundaries.
Though they almost never attack humans, wolves are considered one of the animal world's most fearsome natural villains. They do attack domestic animals, and countless wolves have been shot, trapped, and poisoned because of this tendency. In the lower 48 states, gray wolves were hunted to near extinction, though some populations survived and others have since been reintroduced.