Gotwald, W. H., Jr.; Billen, J. P. J. 1998. In memoriam Jozef K.A. van Boven (1915-1997). Sociobiology 31:143-145.

Buschinger, A.; Billen, J. P. J. 2000. Morphology and ultrastructure of a specialized bacterial pouch in the digestive tract of Tetraponera ants (Formicidae, Pseudomyrmecinae). Arthropod Structure and Development 29:259-266. PDF

Billen, J. P. J. 2002. A novel epithelial intramandibular gland in the ant Pyramica membranifera (Hymenoptera, Formicidae). Belgian Journal of Zoology 132:175-176.

Gobin, B.; Billen, J. P. J. 1996. Trail following in army ants (Hymenoptera, Formicidae). Netherlands Journal of Zoology 46:272-280.

Morgan, E. D.; Billen, J. P. J. 1998. Pheromone communication in social insects: sources and secretions. Pp. 3-33 in: Vander Meer, R. K.; Breed, M. D.; Espelie, K. E.; Winston, M. L. (eds.) 1998. Pheromone communication in social insects. Ants, wasps, bees, and termites. Boulder: Westview Press, x + 368 pp.

Wilson, E. O.; Billen, J. P. J. 2008. Social insect histology from the nineteenth century: the magnificent pioneer sections of Charles Janet. Arthropod Structure and Development 37:163-167. PDF

Gobin, B.; Billen, J. P. J. 1994. Spécificité de la phéromone de piste chez Crematogaster scutellaris et Crematogaster laestrygon. Actes des Colloques Insectes Sociaux 9:35-39.

Ito, F.; Billen, J. P. J. 1998. Larval hemolymph feeding and oophagy: behavior of queens and workers in the primitive ponerine ant Prionopelta kraepelini (Hymenoptera, Formicidae). Belgian Journal of Zoology 128:201-209.

Schoeters, E.; Billen, J. P. J. 1999. Les organes neurohemaux perisympathiques des fourmis et differences entre les castes femelles. Actes des Colloques Insectes Sociaux 12:139-142. PDF

Schoeters, E.; Billen, J. P. J. 1994. Nouvelles données structurales sur la glande à venin chez Atta sexdens rubropilosa et Myrmica sabuleti (Hymenoptera, Formicidae). Actes des Colloques Insectes Sociaux 9:67-73.

Billen, J. P. J. 2002. XIV International Congress of IUSSI. The Golden Jubilee Proceedings. 27 July - 3 August 2002, Hokkaido University, Sapporo, Japan. Sapporo: XIV International Congress of IUSSI, 233 pp.

Notes: Billen (ed.)

Billen, J. P. J. 2009. Occurrence and structural organization of the exocrine glands in the legs of ants. Arthropod Structure and Development 38:2-15. PDF

Billen, J. P. J. 2000. A novel exocrine gland in the antennal scape of the army ant Eciton burchelli. Belgian Journal of Zoology 130:159-160.

Billen, J. P. J. 1998. Exocrine glands in the legs of ants. [Abstract.]. P. 64 in: Schwarz, M. P.; Hogendoorn, K. (eds.) 1998. Social insects at the turn of the millennium. Proceedings of the XIII International Congress of IUSSI. Adelaide, Australia. 29 December 1998 - 3 January 1999. Adelaide: XIII Congress of IUSSI, 535 pp.

Petralia, R. S.; Vinson, S. B. 1980. Internal anatomy of the fourth instar larva of the imported fire ant, Solenopsis invicta Buren (Hymenoptera : Formicidae). International Journal of Insect Morphology and Embryology 9:89-106. PDF

Bressac, C.; Rabitsch, W. 1969. Observations sur la structure du système nerveux céphalique (cerveau, masse sous-œsophagienne et complexe rétro-cérébral) de la fourmi Aphænogaster senilis (Mayr, 1853) (Hymenoptera Myrmicinae). Insectes Sociaux 16:135-148.

Masson, C.; Gabouriaut, D. 1973. Ultrastructure de l'organe de Johnston de la Fourmi Camponotus vagus Scop. (Hymenoptera, Formicidae). Zeitschrift für Zellforschung und Mikroskopische Anatomie 140:39-75.

Délye, G. 1965. Anatomie et fonctionnement des stigmates de quelques Fourmis (Hyménoptères Formicidæ). Insectes Sociaux 12:285-290.

Buchner, P. 1918. Vergleichende Eistudien I. Die aksessorischen Kerne des Hymenoptereneiers. Archiv. fur Mikros. Anat. 91:1-202.

Notes: Oogenesis, karyology

Hackmann, A.; Delacave, H.; Robinson, A.; Labonte, D.; Federle, W. 2015. Functional morphology and efficiency of the antenna cleaner in Camponotus rufifemur ants. Royal Society Open Science 2:150129. 10.1098/rsos.150129 PDF

Federle, W.; Endlein, T. 2004. Locomotion and adhesion: dynamic control of adhesive surface contact in ants. Arthropod Structure and Development 33:67-75. 10.1016/j.asd.2003.11.001 PDF

Billen, J. P. J.; Al-Khalifa, M. S.; Rilva, R. R. 2017. Pretarsus structure in relation to climbing ability in the ants Brachyponera sennaarensis and Daceton armigerum. Saudi Journal of Biological Sciences 24:830-836. 10.1016/j.sjbs.2016.06.007 PDF

Dashman, T. 1953. Terminology of the pretarsus. Annals of the Entomological Society of America 46:56-62. PDF

Basibuyuk, H. H.; Quickle, D. L. J. 1999. Grooming behaviours in the Hymenoptera (Insecta): potential phylogenetic significance. Zoological Journal of the Linnean Society 125:349-382. 10.1111/j.1096-3642.1999.tb00597.x PDF

Federle, W.; Brainerd, E. L.; McMahon, T. A.; Hölldobler, B. 2001. Biomechanics of movable pretarsal adhesive organ in ants and bees. Proceedings of the National Academy of Sciences of the United States of America 98:6215-6220. 10.1073/pnas.111139298 PDF

Federle, W.; Rohrseitz, K.; Hölldobler, B. 2000. Attachment forces of ants measured with a centrifuge: better 'wax-runners' have a poorer attachment to a smooth surface. Journal of Experimental Biology 203:505-512. PDF

Federle, W.; Riehle, M.; Curtis, A. S. G.; Full, R. J. 2002. An integrative study of insect adhesion: mechanics and wet adhesion of pretarsal pads in ants. Integrative and Comparative Biology 42:1100-1106. PDF

Notes: Oecophylla smaragdina

Endlein, T.; Federle, W. 2015. On heels and toes: how ants climb with adhesive pads and tarsal friction hair arrays. PLoS ONE 10:e0141269. 10.1371/journal.pone.0141269 PDF

Notes: Oecophylla smaragdina

Federle, W.; Baumartner, W.; Hölldobler, B. 2004. Biomechanics of ant adhesive pads: frictional forces are rate- and temperature-dependent. Journal of Experimental Biology 206:67-74. 10.1242/jeb.00716 PDF

Schwarz, S.; Narendra, A.; Zeil, J. 2011. The properties of the visual system in the Australian desert ant Melophorus bagoti. Arthropod Structure and Development 40:128-34. 10.1016/j.asd.2010.10.003 PDF