The Tools That Jack Built [From the Editor]

Humans are not the only animal species that makes and uses tools. Wikipedia has a photo of what appears to be a gorilla using a stick to gauge water depth. Likewise, elephants use rocks for various tasks. If using tools is a measure of intelligence, these animals are clearly intelligent. Although most animals use no tools other than their paws and teeth, some of them, such as squirrels and dogs, seem pretty smart as well.