According to Plutarch, the queen of Cleopatra VII after the defeat at Actium in 31 BCE for several months she picked up strong poisons, the effectiveness and degree of pain of which she checked on prisoners.
To her surprise, she found that fast-acting poisons were more painful than slower-acting poisons. She also conducted tests on animals. Ultimately, she concluded that only the bite of the viper did not cause convulsions and severe pain.
On the other hand, a bitten person becomes stunned and gradually weakens, which over time leads to a state similar to people suffering from deep sleep.
