sexual cannibalism

Sexual cannibalism is an animal behavior where one mate eats all or part of the other during courtship or copulation. This behavior is observed in various invertebrates, including arachnids, insects, and cephalopods.1

Why It Happens

• For Females: Consuming a mate provides essential nutrition and energy, which can be passed on to offspring. Females are more likely to engage in sexual cannibalism when hungry, and those that do may produce larger egg cases with more numerous offspring.1
• For Males: Despite the ultimate cost, males may benefit by increasing their chances of reproductive success. If mating opportunities are scarce, a chance of dying during mating might be a worthwhile risk. Additionally, the male's body can contribute to the female producing more viable offspring, ensuring his genes are passed on. In some cases, prolonged mating after being eaten can also increase fertilization success and reduce sperm competition.1

Examples in the Animal Kingdom

• Redback Spiders: Males are eaten by females in a significant percentage of matings.1
• Mantis: Females, much larger and stronger than males, may eat them after mating to gain nutrients for egg production.2
• Octopus: Some female octopuses eat their mates after copulation.2
• Green Anacondas: Females may eat one or more males after mating in a "breeding ball" to gain nutrients for offspring.2
• Scorpions: Males may be eaten by females to provide sustenance for the energy-intensive process of giving birth to live young.2