"Fer-de-lance" meaning 'spear head, is a common name given to the variety of snakes from the genus Bothrops, a group of snakes also known as pit vipers. However, many scientists now restrict the name 'fer-de-lance' to the Martinican species, Bothrops lanceolatus.
Like other pit vipers Bothrops species have two indentations or 'pits' behind and above the nostrils which can detect a rise or drop in temperature of just 0.001°C, allowing it to detect warm-blooded mammals. These 'pits', coupled with its tongue to 'taste' the air, allow the fer-de-lance to strike with great accuracy even in total darkness.
Bothrops species are able to climb and swim. Their natural habitat is forest, but it is often found on plantations and in run-down houses, as it can find a ready supply of rats and mice there. This unfortunately brings it into contact with humans. It will usually flee if disturbed, but can also defend itself vigorously, striking as soon as an enemy is within reach.
Read More: Fer De Lance Habits