Animals exhibit various behaviours which are crucial for their survival. Some behaviour may seem quite counterintuitive, but it can mean the difference between life and death. Hence, these behaviours are the result of millions of years of evolution. From the very first cells to complex multicellular organisms that we see today, life has come a long way.
Insects are one of the earliest forms of life to evolve, with the very first fossil records dating back to at least 412 million years. This means they have had more time to evolve and adapt, perfecting many of the traits and characteristics that we observe in insects today.
Their evolutionary success can be seen through their vast species diversity, with over 900,000 species of insects documented till date. However, some insects exhibit baffling behaviour that makes entomologists scratch their heads. From cannibalism to homosexuality, explore strange insect behaviours.
Technically, spiders are not insects, but they all fall under invertebrates. The black widow spider is one of the most venomous spiders on the planet. So, getting bitten by one means certain death. The female spider is much larger than the males, with a shiny black body and distinctive red hourglass marking on the underside of the abdomen. What is far more interesting is the mating habits of the species. It has been known that the female will kill and consume the male soon after mating.
In some cases, the males are killed even before the mating process is complete. The females are not aggressive and do not exhibit predatory behaviour towards the males. The male, especially in the redback species (Latrodectus hasseltii), does a kind of “somersault” and flings his abdomen into the fangs of the females. This is when the male is killed and consumed by the female. Scientists are not able to explain this behaviour despite the obvious disadvantage to males. One speculation is that the males will no longer be able to reproduce; hence, the “sacrifice” can be seen as a better evolutionary strategy to ensure that the male contributes nutrition to the eggs rather than prolonging life.
Trap Door Ants
Spiders are the only known invertebrates to create traps for hunting. However, a recently discovered species of ants, Allomerus decemarticulatus, also build traps to ensnare prey.
The trap it builds is very elaborate. It is used to capture prey much larger and quicker than the ants. The ant uses the stem of its host plant and binds it with fungal mycelium. The resulting structure resembles a perforated platform with intricate tunnels underneath. The ants wait under the perforations with their jaws open. When a prey walks on this platform, the ants quickly clamp down on it, immobilizing it in the process. The way the ant kills its prey is rather gruesome: After clamping on to the legs and antenna of the prey, the ants start pulling it apart. Eventually, the prey is ripped apart and carried back to the ant’s nest where it is stored or consumed.
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