The majority of snakes are non-poisonous and harmless animals. Some of the common poisonous snakes of Bangladesh are cobra, karit, pit-viper, rattle –snake, russls snake, corla-snake, and sea-snakes. The identification of poisonous and nonpoisonous snakes is very simple. The following key will serve to distinguish poisonous snakes from non-poisonous snakes:
- If it is a marine snakes with the tail laterally compressed it is poisonous.
2. In a terrestrial snake the tail is rounded or cylindrical and not compressed. Examine its ventral scales.
(a) if all the ventral scales are small or the ventral scales are somewhat broad, then it is a non-poisonous snake.
(b) If the ventral scales are large transverse plates extending fully across the ventral said or belly, the snake may be poisonous or non-poisonous. To find out examine the dorsal surface of the head.
(c) If all the dorsal scales of the head are small, than it may be a viper .
(d) If there is a loreal-pit between the nostril and the eye, than it is dait-viper.
(e) If dorsal said of the hade has both small scales and large shields, the snake may or may not be poisonous, ascertain look at side of the hade.
3. If the third supra-labial shield touches the nostril and eye, then it is a poisonous, snake, may be cobra, king-cobra, or coral snake.
4.If the upper said of the head has both small scale and large shields but there is no loreal-pit and third supra-labial shield dos not touch the eye, thane examine the back of the snake and ventral said of the lower jaw.
(a) The middle row of scales on the back called vertebral may be larger then other.
(b) Ventral said lower jaw has fourth infra-labial shield larger than the others. If both (1) and (2) characters are present, then it is a krait.
(5) If the snake has small scale and large shields on the head but does not have the characters of cobra, krait or coral-snake, then it is non-poisonous