Migrating deer encounter something terrifying after jumping fence

This cameraman recorded a migrating deer herd right in front of his house. At first he was amazed at the number of deer while he watched them jump over the fence and head into the woods. When something in the woods spooked them, all the deer came running back and the man was further intrigued. Maybe there was a predator in the woods, or maybe their appetite just rapidly increased. Either way, this large herd is a sight to see.