Stealing a handful of mole rats is one thing, but some ant species take kidnapping to a whole new level. On the forest floor of California’s Sierra Nevada, red ants (Polyergus mexicanus) launch frenzied raids on the nests of nearby black ants (Formica accreta) and steal hundreds of their pupae.
The pupae are carried back to the red ant nest, and when they hatch, the kidnappers coat them in secretions from specialised glands. This bathes the captives in the scent of the colony, fooling them into thinking they belong. From that moment on, the captives work for the red ants, maintaining their nest, tending their young and foraging for food.
Slave-making ants can’t feed themselves, because their jaws are the wrong shape for foraging or processing food. Not so the captive ants, who feed their kidnappers by regurgitating food into their mouths.
The whole scenario is known as obligate social parasitism. ‘Parasitism’ because one species gains resources at the others expense. ‘Social’ because the whole colony is in on it. And ‘obligate’ because the parasite has no choice. Slave-making ants would be unable to survive without the help of the species they kidnap.
Top image: William Cho, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons
