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10 Animals That Kill Their Mates (Pictures)

While people sometimes say “you are what you eat,” there are some animals that take that statement literally! There are certain animal species that kill and eat their mates! This cannibalistic behavior may seem strange, but there are several explanations for this behavior.

Some experts believe that animals that kill their mates because the nutritional value of the animal is greater than its value as a mate. Others believe that females cannibalize unfit mates! Learning more about these animals can help you to better understand their behavior.

Collage photo animals that kill their mates

10 Animals That Kill Their Mates

1. Orb weaver Spiders

Orb Weaver
Image by Frank Dilorenzo from Pixabay

These spiders get their name from the large, spiral-shaped webs that they weave. There are more than 3,000 different orb weaver species around the world, and a number of these species are known for killing and eating their mates. Since females are much larger than males are, males are easy to prey on.

Even though males are much smaller than females, they still have some defenses. After mating, males try to catapult themselves away from females! If these spiders are successful, they can get away from their mates and mate again, but the process won’t necessarily end well for the male.

2. Labord’s Chameleon

Labord's chameleon
Male Labord’s Chameleon | image by Frank Vassen via Flickr | CC BY 2.0

These tiny chameleons have violent mating habits that sometimes result in death! Not only do males fight with each other to attract mates, but females and males fight each other while mating.

This is usually fatal, and both males and females die shortly after breeding. These chameleons have an extremely short lifespan and typically live for four to five months. Mating has such a high fatality rate that until their eggs hatch, the entire Labord’s chameleon population disappears.

3. Octopuses

Image by Sebastian Ganso from Pixabay

Octopuses are highly intelligent, but mating can still be a big risk for these cephalopods. In order to mate, male octopuses must place one of its arms inside of the female’s mantle cavity. This process can take hours, and if a female becomes agitated, it could end badly for the male.

While mating, female octopuses can use their arms to strangle their mate. Afterwards, they feed on the male’s body. To avoid becoming a meal, males take advantage of their long arms and mate from a distance.

4. Bees

Image by Rebekka D from Pixabay

Bees are known for collecting pollen and making honey, but drone bees don’t engage in this behavior. These bees only have one purpose: to mate with a queen bee. Mating is fatal for drone bees, and after a bee has finished mating, its body falls away, leaving part of its endophallus attached to the queen.

Typically, a drone bee won’t live more than 90 days. If food is scarce, drone bees may even die before they have the chance to meet. Worker bees will sometimes push drone bees out of hives to make sure that there’s enough food available for the queen.

5. Anacondas

Anaconda in the river
Anaconda in the river | image by Fernando Flores via Flickr | CC BY-SA 2.0

Female anacondas aren’t able to eat during their pregnancy, and because of that, they’ll sometimes eat mates to get the nutrients they need for the next seven months! After mating, sometimes anacondas will squeeze their mates to death and then feed on their bodies. Male anacondas can be a valuable source of protein.

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Surprisingly, male anacondas don’t try to avoid being eaten. In fact, males are actually more attracted to much larger females. Since female anacondas can be more than five times larger than males, it isn’t difficult for them to turn their mates into a snack!

6. Black Widow Spiders

Black Widow Spider
Black Widow Spider | image by CanyonlandsNPS via Flickr

Mating is a dangerous activity for many spiders, including the black widow! True to their name, females often kill and eat their mates, making themselves widows!

While this behavior is most commonly seen in females, male black widows may also eat their mates! According to researchers, male spiders sometimes eat older females. Males will also seek out well-fed partners to protect themselves from cannibalism.

7. Sea Slugs

Sea Cucumber underwater
Sea Cucumber underwater | image by NOAA Ocean Exploration via Flickr | CC BY-SA 2.0

Many sea slug species are hermaphrodites. While these species are capable of self-fertilization, some of these sea slugs still prefer to mate with a partner. Unfortunately, this process doesn’t always end well for the sea slug.

The nudibranch is a type of sea slug that’s known for its cannibalism! These sea slugs are carnivores that sometimes feed on each other after mating. In some cases, these sea slugs may even resort to cannibalism before they’ve had the chance to mate.

8. Sagebrush Crickets

Sagebrush cricket
Sagebrush cricket | image by Kevinjudge via Wikimedia Commons | CC BY-SA 4.0

Many animals kill their mates after mating, but sagebrush crickets will actually feed on their partners during mating! Females will eat a male’s wings and drink the juices that ooze out.

This process can be fatal for sagebrush crickets, but males sometimes survive being eaten, allowing them to mate again. However, since a wingless cricket can’t provide a snack for females, they’re a far less attractive mate.

9. Praying Mantises

Praying mantis
Praying mantis

The praying mantis has a varied diet that includes spiders, grasshoppers, and even small lizards and birds! In some cases, they may also eat their mates! Females are much larger than males, and they sometimes bite off the male’s head immediately after mating.

Even though these insects are well-known for this behavior, the praying mantis is less likely to eat its mate than you might think. Studies show that around 13 to 28 percent of praying mantises engage in cannibalism after mating. A well-fed praying mantis probably won’t eat its mate, but a hungry one might!

10. Jumping Spiders

jumping zebra spider
Jumping zebra spider | Image by Peter Schmidt from Pixabay

Like many types of spiders, jumping spiders have extremely poor vision. Due to their weak eyesight, it can make it difficult for them to distinguish between different types of spiders. It’s not unusual for male jumping spiders to try to attract the attention of any female spider nearby, including spiders of a different species.

This behavior means that male jumping spiders are vulnerable to many female spiders, not just the females that they mate with. If a male approaches a spider species that eats other spiders, there’s a good chance that he won’t walk away. When males are able to mate successfully with females, they’ll usually try to escape before jumping before the females can eat them.