insects utilize defensive regurgitation. The eastern tent caterpillar regurgitates a droplet of digestive fluid to repel attacking ants. Similarly, larvae of the noctuid moth regurgitate when disturbed by ants. The vomit of noctuid moths has repellent and irritant properties that help to deter predator attacks. Suicidal altruism An unusual type of predator deterrence is observed in the Malaysian exploding ant. Social hymenoptera rely on altruism to protect the entire colony, so the self-destructive acts benefit all individuals in the colony. When a worker ant's leg is grasped, it suicidally expels the contents of its hypertrophied submandibular glands, expelling corrosive irritant compounds and adhesives onto the predator. These prevent predation and serve as a signal to other enemy ants to stop predation of the rest of the colony. Escaping Flight The normal reaction of a prey animal to an attacking predator is to flee by any available means, whether flying, gliding, falling, swimming, running, jumping, burrowing or rolling, according to the animal's capabilities. Escape paths are often erratic, making it difficult for the predator to predict which way the prey will go next: for example, birds such as snipe, ptarmigan and black-headed gulls evade fast raptors such as peregrine falcons with zigzagging or jinking flight. In the tropical rain forests of Southeast Asia in particular, many vertebrates escape predators by falling and gliding. Among the insects, many moths turn sharply, fall, or perform a powered dive in response to the sonar clicks of bats. Among fish, the stickleback follows a zigzagging path, often doubling back erratically, when chased by a fish-eating merganser duck. Autotomy Some animals are capable of autotomy (self-amputation), shedding one of their own appendages in a last-ditch attempt to elude a predator's grasp or to distract the predator and thereby allow escape. The lost body part may be regenerated later. Certain sea slugs discard stinging papillae; arthropods such as crabs can sacrifice a claw, which can be regrown over several successive moults; among vertebrates, many geckos and other lizards shed their tails when attacked: the tail goes on writhing for a while, distracting the predator, and giving the lizard time to escape; a smaller tail slowly regrows. History of observations Aristotle recorded observations (around 350 BC) of the antipredator behaviour of cephalopods in his History of Animals, including the use of ink as a distraction, camouflage, and signalling. In 1940, Hugh Cott wrote a compendious study of camouflage,