Sea snakes are reptiles that live in the ocean, where they ride the waves, dive underwater, catch fish and shrimp, and have children. In the late Mesozoic era 70 million to 23,000 million years ago, part of the amphibians finally said goodbye to the water, completely settled on land, thus evolving into reptiles - snakes. However, some of the snakes remained nostalgic and returned to the cradle that nurtured their ancient predecessors, becoming what are known today as sea snakes.

Sea snakes like to live in shallow waters around continental shelves and islands, and are rarely seen in open waters deeper than 100 meters. While some of them prefer to stay in mixed water on sandy or muddy bottoms, others prefer the clear water around coral reefs. Sea snakes dive at different depths, some deeper, some shallower. Sea snakes have been seen at depths of 40 to 50 meters. Shallow-water sea snakes generally dive for no more than 30 minutes, stay on the surface of the time is also very short, each time just to show their heads, and soon inhale a breath on the submerged again. Deep-water sea snakes stay at the surface longer, especially in the evening and at night. They can dive for up to two to three hours.

Sea snakes are selective about what they eat, and many have feeding habits related to their size. Some sea snakes have large, thick bodies with long, thin necks and surprisingly small heads, and such snakes feed almost exclusively on burrowing eel fronts. Some sea snakes feed on fish eggs, and these snakes have small teeth and small fangs and venom glands. Some sea snakes like to feed on fish with venomous spines, and in the Northern Sayan Sea of the Philippines, there is a sea snake that feeds exclusively on the eel-tailed catfish. Eel-tailed catfish have venomous spines that are so painful that they can seriously injure a person, but sea snakes don't care about that. In addition to fish, sea snakes also attack larger creatures.

The venom of sea snakes is among the most powerful animal poisons. Hook-billed sea snake venom is twice as toxic as cobra venom and 80 times more toxic than sodium cyanide. Sea snake venom is composed of neurotoxins similar to cobra venom, however, strangely enough, the parts of the body damaged by its venom are mainly the random muscles, not the nervous system. Sea snake bite painless, its toxicity attack and there is a period of incubation, by the sea snake bite 30 minutes or even 3 hours after there are no obvious symptoms of poisoning, however, this is very dangerous, easy to make people paralyzed. In reality, sea snake venom is absorbed by the body very quickly, the first thing you feel after poisoning is muscle weakness, soreness, drooping eyelids, jaw straightening, a bit like the symptoms of tetanus, while the heart and kidneys will also be seriously damaged. Those bitten may die within a few hours to a few days. Most sea snakes injure people when they are harassed.