Pair of venom producing glands are found in all the poisonous snakes, which are positioned below and behind the eyes. They are accompanied by a pair of maxillary teeth called fangs.
We can identify two types of venom producing glands.
1. True Venom
Elapids, Viperids and sea snakes have this type of venom glands. The fangs are situated anteriorly.
2. Duvernoy's glands
Found in some Colubrids. Relatively small gland situated posteriorly. Venom is ejected through a posterior fang. Colubrids with well developed Duvernoy's glands are mildly poisonous.