A life-saving act. Spider pretends to be ant to avoid being eaten
A spider’s role as an ant might not win it an Oscar, but it could save its life.
A Cornell University research published in Proceedings of the Royal Society B. reveals that some jumping spiders pretend to be ants. The reason behind the behaviour is quite simple: while ants are well-armed with bites, stings and formic acid, the jumping spiders – Myrmarachne formicaria – can’t do much more than run on their eight legs when attacked.
Because insect predators tend to prefer spiders over ants, appearing to be an ant confers significant protection and can save a spider’s life.
Cornell University scientists used multiple high-speed cameras and behavioral experiments to pinpoint how the spider’s movements mimic ants. Ant-mimicking spiders walk using all eight legs but pause frequently to raise their forelegs to mimic ant antennae. When walking, they take winding trajectories of about five to 10 body lengths, which made them look like ants following pheromone trails. While the researchers could see what the spiders were doing thanks to high-speed cameras, many potential predators have slower visual systems, so that to them the mimics appear to be moving just like an ant would.
The researchers note that the findings “highlight the importance of dynamic behaviors and observer perception in mimicry.”
Protective mimicry is a remarkable example of adaptive evolution: Moths can be colored like butterflies and grasshoppers may look like tiger beetles.