page_title: Hypnale hypnale
section_title: Behavior
hierarchical_section_title: Hypnale hypnale / Behavior
caption_attribution_description: English: At Kandalama
context_page_description: Hypnale hypnale is a venomous pit viper species endemic to India and Sri Lanka. Common names include the hump-nosed viper, Merrem's hump-nosed viper and others listed below at § Common names.
  No subspecies are currently recognized.
context_section_description: Hypnale hypnale is active during early morning and night. It spends the day in leaf litter and thick bushes. This species can be found on the stream side basking during the sunrise. Although it is a slow mover, it is capable of fast strikes. It has an irritable disposition and will vibrate its tail when annoyed, a behavior it has in common with other pit vipers, especially rattlesnakes of the genera Crotalus and Sistrurus. It has been described as nocturnal, terrestrial, and aggressive when disturbed. It is the snake to cause the highest number of recorded snake bites in Sri Lanka.
caption: At Kandalama, note the flattening body when threatened
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