Unlike most venomous snakes that will attack when cornered or while being handled, the king brown snake, or Mulga snake will attack without provocation while the victim is sound asleep. A study of 27 Mulga snake bites revealed that in seven of the attacks, the victims were sleeping, usually between midnight and 5 a.m.
The Mulga snake, Pseudechis australis, is one of Australia's largest and longest venomous reptiles. Growing up to 9.8 feet in length and weighing between 6.5 and 13.2 pounds, they are a formidable killing machine. They usually prey on mice and other small animals in the wild.
Of the 27 victims in the study, 10 people had encountered the reptile by accident. Researchers say the fact that seven of these people being bitten while sleeping "is noteworthy because it represents 70 percent of identified cases involving bites without intentional contact, and suggests that bites sustained during sleep may be more common than previously reported."
Mulga snake venom contains myotoxins, basic peptides that can lead to severe muscle necrosis. This potent soup, when injected into a small animal will paralyse it instantaneously, preventing it from escaping and eventually causing death. Today, black snake antivenom is used to treat bites from the Mulga snake.
While it is well known that venomous snakes don't always inject their venom when they bite, of the 27 people bitten in the study, 21 victims showed positive signs of envenomation. These victims had symptoms that included bleeding, vomiting, abdominal pain and some diarrhea.
Dr. Sean Bush, a professor of emergency medicine at East Carolina University, and a specialist in snake venom, said, "The thing that was surprising about this study was there was a higher-than-expected rate of envenomation." Although Dr. Bush was not a member of the research team, he suggested that the large size of the reptile and the size of its fangs may be the reason for the high envenomation rate found.
The study authors are still speculating as to why the Mulga snake bites people while they are asleep. They suggested a couple of scenarios, such as, "the snake may have been attracted to the victim's body heat," or, "the snake was just initially looking for rodents that might have been attracted by a trash can close to a victim's home."