"....[M]any termite workers defecate so violently that they eviscerate or their guts literally explode, spewing out noxious materials onto their enemies. This phenomenon is called dehiscence, and some termites have especially enlarged abdomens, full of nasty chemicals, ready to dehisce. The termite, of course, dies some time afterwards. Autothysis is a similar strategy, but in this case frontal glands in the head or thorax are enlarged and erupt explosively, releasing noxious chemicals in a similar way."
cronodon.com/BioTech/Insect_Society.html

here's the best citation i could find about it:

www.springerlink.com/content...mdf04ln/

C. Bordereau, A. Robert, V. Van Tuyen & A. Peppuy (1997). Suicidal defensive behavior by frontal gland dehiscence in Globitermes sulphureus Haviland soldiers (Isoptera). Insectes Sociaux 44 (3): 289–297. 



also, in ants:
en.wikipedia.org/wiki/Camp..._saundersi

"Camponotus saundersi is a species of ant found in Malaysia.
It has a defensive behavior of self-destructing. Two oversized, poison-filled mandibular glands run the entire length of the ant's body. When combat takes a turn for the worse, the ant violently contracts its abdominal muscles to rupture its body and spray poison in all directions."

The Chemistry of Exploding Ants, Camponotus SPP. (Cylindricus COMPLEX)
T. H. Jones, D. A. Clark, A. A. Edwards, D. W. Davidson, T. F. Spande and R. R. Snelling
Journal of Chemical Ecology , Volume 30, Number 8 / August, 2004


i'm going to seek these articles, and begin consideration of the pressures and relationships that have lead to the evolution of this strategy. i suppose it's not really all that perplexing, but fascinating nonetheless.