, Volume 94, Issue 4, pp 326–332 | Cite as

Opposable spines facilitate fine and gross object manipulation in fire ants

  • Deby Cassill
  • Anthony Greco
  • Rajesh Silwal
  • Xuefeng Wang
Short Communication


Ants inhabit diverse terrestrial biomes from the Sahara Desert to the Arctic tundra. One factor contributing to the ants’ successful colonization of diverse geographical regions is their ability to manipulate objects when excavating nests, capturing, transporting and rendering prey or grooming, feeding and transporting helpless brood. This paper is the first to report the form and function of opposable spines on the foretarsi of queens and workers used during fine motor and gross motor object manipulation in the fire ant, Solenopsis invicta. In conjunction with their mandibles, queens and workers used their foretarsi to grasp and rotate eggs, push or pull thread-like objects out of their way or push excavated soil pellets behind them for disposal by other workers. Opposable spines were found on the foretarsi of workers from seven of eight other ant species suggesting that they might be a common feature in the Formicidae.


Functional morphology Motor skills Forelimbs Tarsi Digits 



The authors thank Baxter Clark, Alan Thrun and Amanda Dominguez for the data contributions, David Brodosi for the technical assistance with the images and three anonymous reviewers for their erudite critiques. Lastly, we thank the managing editor, Tatiana Czeschlik, for her encouragement. Experiments conducted on these organisms comply with the current laws of the country in which they were performed. This project was funded in part by the ESPG Program of Distinction at USF St. Petersburg.


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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Deby Cassill
    • 1
  • Anthony Greco
    • 2
  • Rajesh Silwal
    • 3
  • Xuefeng Wang
    • 4
  1. 1.Department of ESP-BiologySt. PetersburgUSA
  2. 2.College of Marine ScienceUniversity of South FloridaTampaUSA
  3. 3.Undergraduate StudentUniversity of South FloridaTampaUSA
  4. 4.Program in Environmental ScienceSt. PetersburgUSA

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