Precision rescue behavior.

<p>In addition to digging near an entrapped nestmate and pulling on its limbs, a very simple form of rescue behavior observed in several ant species, <i>C. cursor</i> ants somehow are able to identify exactly what obstacle holds the victim in place, to transport sand away from that obstacle, and then to target their bites precisely to it alone, excavating sand as necessary to expose the obstacle further. We have labeled this behavior “precision rescue.” Here, a <i>C. cursor</i> rescuer already has transported sufficient sand away from the victim, exposing the nylon thread snare holding its nestmate in place (part of the white filter paper has been exposed as well), and is pictured biting the snare that holds the victim to the paper. Carefully aimed, snare biting never is misplaced, even though the snare has been tied snugly around the pedicel (waist) of the victim and is in direct contact with the victim's body. Photograph by Paul Devienne.