Autohaemorrhaging

Autohaemorrhaging, or reflex bleeding, is the action of animals deliberately ejecting blood from their bodies.

The blood of these animals usually contains toxic compounds, making the behaviour an effective chemical defense mechanism.

This form appears to serve a deterrent effect, and is used by animals whose blood does not seem to be toxic.

Beetles may lose up to 13% of their net body weight as a consequence of expelling haemolymph.

The ejection of blood puts organisms at risk of cannibalism from other members of their species.

Horned lizard showing evidence of autohaemorrhaging
A West Indian wood snake displaying autohaemorrhaging. The eyes are fully flooded with blood and some is emerging from the mouth.
An inactive prepupa Asian ladybeetle autohaemorrhaging, resulting from cannibalism by an adult of the same species.