05/31/2026
The male redback spider somersaults into the female's fangs on purpose. He has been doing this for millions of years.
What looks like predation is actually paternal investment taken to its logical extreme. The male redback, Latrodectus hasselti, is roughly 1% the body mass of the female. He contributes almost nothing in size. So evolution found another currency: his entire body.
The mechanics are specific. During copulation, the male performs an abdominal somersault that positions his abdomen directly over the female's chelicerae. She begins consuming him while he continues to mate. Studies by Maydianne Andrade at the University of Toronto found that males who are consumed during mating fertilize significantly more eggs than males who escape. The act of being eaten actually prolongs copulation time, giving his s***m a competitive advantage over any rival who mated before him.
There is also a second male in most of these encounters. Females mate with multiple partners, and the male who sacrifices himself tends to displace the s***m of competitors. His death is not just nutrition. It is a reproductive strategy that outcompetes survival.
The female's venom liquefies his tissues rapidly, and the resulting proteins feed her directly through the mating period, when her metabolic demand is highest. His body does not go to the eggs in any abstract sense. It goes to the female's energy budget at the exact moment she needs it most, and that surplus translates into larger, better-provisioned egg sacs.
He gets one shot. He takes it completely.
