[SteveStromberg]

Perhaps the most feared snake of all, however, is the fer-de-lance - Central America's most lethal. Like most snakes, it prefers to be left alone, but it does sometimes bite humans with little provocation. The fer-de-lance bites several hundred people each year in Costa Rica, mostly agricultural workers who are in the wrong place at the wrong time.

The snake hunts by ambush, lying camouflaged within the leaf litter on the forest floor. Many human victims simply get too close for the snake's comfort without realizing it's there - until the strike.

A bite is serious business because the snake's venom is incredibly toxic. Even a drop plays havoc within living tissue, devastating the victim's veins and capillaries. Internal swelling is so severe that doctors often remove the skin to release the pressure, and gruesome wounds result.