Bill Wilson, age 12, of Douglass, Kansas, for his question:
What is a pit viper?
In the past, certain communities relied on a snake pit to maintain law, order and peaceable behavior. Amass of writhing snakes was on display, deep down in a steep sided hole. It was intended to deter the average citizen from crime. When this failed, the guilty party might be suspended over the snake pit as a warning or dumped down the hole. However, this hair raising historic item has nothing at all to do with why certain snakes are called pit vipers.
The vipers and pit vipers are large and medium sized snakes. They are found in the Americas and parts of Asia and one species crawled from Asia to eastern Europe. None live in Australia or Africa. As a rule these snakes are classed in separate families. The so called true vipers are in the family Viperidae, the pit vipers are in the family Crotalidae.
Both families are viciously venomous. Both have poisonous fangs and a deadly talent for striking their warm blooded victims on target. However, the pit vipers have an extra talent. They can strike down their warm blooded victims in the dark. They can do this because they have a remarkable pair of sense organs called pits.
The Spanish call these snakes cuatro narices which means four nostrils. It is easy to mistake the famous pit organs for an extra pair of nostrils, located between the true nostrils and the snakey eyes. Scientists did not mistake these slight depressions for nostrils. But years ago, they did mistake them for snakey ears.
Like an inner ear, the pit organ is located inside the skull. It has an outer and inner cavity separated by a transparent membrane teeming with highly sensitive nerve endings. This membrane resembles an eardrum. However, pit vipers proved to be as deaf as all other snakes. Obviously there had to be another explanation.
The breakthrough came in the 1930s. Researchers tested pit like organs on certain non vipers and found that they can detect temperature variations. Tests soon proved that the pit viper's pits can do the same thing, only better. He uses these amazing organs to detect the presence and estimate the location of a warm blooded animal. With their help, he can strike dorm his prey with deadly accuracy even in the dark.
In North America we have more than our share of sinister pit vipers: The list includes all our rattlesnakes, our copperheads and water moccasins.
Some pit vipers of the Old World lay eggs, others give birth to live young. Our rattlers and their venomous relatives bear live young. Actually the mother snake retains the eggs in her body until the embryos are fully developed. The newborn snakes have their pits and fangs all set to strike.