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.
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.
Females are much larger than males, and they sometimes bite off the male’s head immediately after mating.
These sea slugs are carnivores that sometimes feed on each other after mating.
True to their name, females often kill and eat their mates, making themselves widows!
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!
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.
Since females are much larger than males are, males are easy to prey on.
Not only do males fight with each other to attract mates, but females and males fight each other while mating.