Rabbit

Rabbits are so familiar as pets and cultural symbols that most people feel they already know them. In practice, rabbits are one of the most physiologically unusual small mammals kept by humans — unable to vomit, capable of dying of fright, running on a digestive system that requires eating their own droppings to function, and expressing happiness through uncontrollable aerial gymnastics.

Facts you didn't know

• 1

  Rabbits eat their own droppings — specifically a soft first-pass pellet called cecotropes, produced in a separate digestive chamber. This re-ingestion is essential to their nutrition: rabbits deprived of cecotropes develop serious deficiencies. The soft droppings are typically consumed directly from the anus before they hit the ground.

• 2

  Rabbits can die of fright. Their physiological terror response can spike heart rate to 300 beats per minute, and severe fear can trigger cardiac failure. Death from fright in rabbits is not a metaphor — it is a documented cause of death in animals that are handled roughly or startled severely.

• 3

  Rabbits' teeth never stop growing — they wear continuously against each other and against food at approximately 3mm per week. Misaligned teeth that can't wear evenly grow progressively into the jaw, causing pain and eventually death if untreated. Dental health is the single largest risk factor for pet rabbit survival.

• 4

  Rabbits cannot vomit. Their digestive system moves in one direction only, meaning hairballs, blockages, and swallowed foreign material that a cat or dog would simply vomit become potentially fatal gastrointestinal obstructions. Gastrointestinal stasis is the leading cause of death in pet rabbits.

• 5

  Rabbits perform a 'binky' when happy — a spontaneous, uncontrolled leap, midair twist, and kick that serves no apparent purpose except expressing exuberance. It happens without warning when the animal feels safe and content, and is entirely involuntary. It is one of the clearest behavioral expressions of positive emotion in any animal.