Helping is common across the animal world and actual rescue is rare. Ants will dig at buried and pull at their limbs, both of which a chemical distress call could release directly, with no understanding required. Nowbahari and colleagues bound test ants with nylon thread under sand and offered them to groups of five , varying who the trapped individual was. What do the rescuers do?
They go for the thread. The ants excavated sand until the nylon snare was exposed, carried the sand away from it, and then bit at the snare itself, a behavior never reported before. They also discriminated carefully, offering aid only to nestmates and not to ants from another colony, another species, a prey item, or an empty snare. Biting a specific object means locating what holds the victim.
Helping behavior is everywhere in the animal kingdom. , meaning action aimed at freeing somebody from a specific predicament, is rare, and the insect examples amount mostly to pulling at a trapped limb or digging away sand.
Both of those could be released directly by a chemical call for help. An ant that detects distress and starts digging needs no model of what is wrong, which is why the behavior, striking as it looks, has not demanded much explanation.
Nowbahari and colleagues built a harder test, simulating a situation they had often seen in the field when collecting these ants and causing sand to collapse. A victim was ensnared with nylon thread and held partly beneath sand, then presented to groups of five nestmates. Six conditions varied the identity of the trapped stimulus, from a nestmate through an ant of another colony or species, a prey item, a chilled nestmate, and an empty snare.
The ants aided only nestmates. More tellingly, they worked the problem in order: excavating sand, exposing the nylon snare, transporting sand away from it, and then biting at the snare itself. Nobody had described before, and it is hard to see how a simple releasing mechanism would guide a rescuer to the precise location of a thread and aim its bites at it.
wat. Digging could be a reflex. Finding the nylon thread and biting at that is something else.
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Digging and pulling can run off a simple released reflex. Targeting the thread cannot, which forces a more demanding account of what the rescuer is tracking.
How do we know?
Nowbahari and colleagues ensnared a test stimulus with nylon thread partly beneath sand and presented it to randomly chosen groups of five nestmates under six conditions, varying the identity of the trapped individual.
What is still unknown
An artificial snare in a laboratory arena, and a sophisticated behavior is not the same as an understanding of it. What the ants represent about the thread is not addressed by the experiment.
Learn something?
Where to next
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