The fer-de-lance is a common Central American snake, a pit-viper, which adapts well to human disturbance, and certainly is the most dangerous and feared snake in Costa Rica because of their very toxic venom. Even a young fer-de-lance probably no more than 30 cm long could administer a lethal bite and the adults can reach over 2 m in length, to which this author can personally attest. Basically an ambush predator, these vipers are extremely well camouflaged and have a tendency to be aggressive. The top of the triangular head can be seen just below left center; it's eye is wide open. This little fellow was spotted by a student who was in the act of grabbing for the large beetle (~ 3 cm long) seen on the left. A watchful attitude and tall boots are very necessary.