You said: "Finally some local genius figured out that the tigers perferred to ambush from behind while the wood cutters were working or resting. They started wearing halloween type masks on the back of their heads and this did reduce the number of attacks!"
National Geographic did a wonderful spread a few years ago about how certain animal species have developed "eye" motifs in their fur, skin or feathers to appear to have "eyes in the back of their head". The unblinking "eye" design serves as a warning to predators. And oddly enough, it seems to work.
And yes, tigers, cougers, leopards - all the big cats - prefer to getcha when your back is turned. An unfortunate number of victims - I am serious - are attacked when they go off the trail to answer the call of nature.....! You're just too tempting a target.
In the high arctic, where polar bears consider humans a tasty treat, it is standard procedure never to exit your shelter without first looking carefully around both sides of the door and overhead - where a polar bear may be waiting very patiently to pounce when a human comes out of the "hole", the same way that fish will emerge from the blow holes in the ice....
You really do need eyes in the back of your head.... Wonder how the ET's missed that one.